Okabe has the characteristics of a lanky young man, with a square jaw and bony cheeks. He has his short black hair swept back and has brown irises, with a small amount of stubble on his chin and cheeks.
Rintaro also wears a lab coat that reaches his shins, over a plain white T-shirt (light gray in the anime), and khaki-colored slacks. The breast pocket of his lab coat has a red pen sticking out, and around his slacks he wears a black military-style canvas belt, with a gold-colored buckle. He has dark socks and wears green slippers when inside the lab.
Ih Steins;Gate 0, he's more professionally-dressed compared to his Steins;Gate counterpart, donning a black dress-shirt, blazer, and slacks held by a black belt with a metal buckle. His hair is more neatly combed, likely to follow university standards. He no longer wears his signature lab coat.
In the game, Okabe appeared much "dustier". His face was pale and unshaven and he seemed a lot more "messy" in contrast to his relatively "clean" appearance in the anime.
In the bonus episodes, when he was portrayed in 'model-like' clothing and poses, he was perceived as attractive.
Okabe is a melodramatic, eccentric and rarely tsundere individual. He is a self-proclaimed mad scientist, who likes to assume his "true name" "Hououin Kyouma" (鳳凰院凶真, Hououin Kyouma), and often uses this to introduce himself to others. For the most part, people do not seem to care and instead address him by his actual name or by 'Okarin' (his nickname), much to his chagrin. This makes him slightly hypocritical as he calls Kurisu a number of names that irritate her to varying degrees. On the other hand, there are some who like his nicknames such as Luka Urushibara with the name "Lukako"(るかこ, Rukako), which affectionately alludes to his feminine nature.
Okabe was also socially inept, to the point that he saw absolutely nothing wrong with yelling in Kurisu's face for calling him 'Okabe' instead of 'Hououin Kyouma' and couldn't understand why she was crying afterwards, even though she explained why sarcastically. His social skills were so poor, in fact, that Kurisu considers the childlike Mayuri to be normal by comparison. However, he isn't hesitant to lend a helping hand to people whom he'd never met, as shown in his first encounter with Luka. Although very intelligent, Okabe is shown to be easily deceived; when Kurisu sent him a D-Mail saying that he was an airhead, he bought her claim that it was a compliment, only realizing later that it essentially meant his head was full of air.
Okabe likes to pose as an agent working against a certain "Organization" which he suggests is always after him, as he believes this kind of image gives him a cool and mysterious aura, though this seems to disappear as the story progresses, with SERN likely replacing the "Organization's" villainous image. In the case of Steins;Gate 0, it's STRATFOR, DURPA, and Russian intelligence. He usually gives off the impression of being delusional and paranoid, displaying eccentric mannerisms such as talking to himself on the phone and engaging in fits of maniacal laughter; he seemed to have a severe case of Chuunibyou at the start of the series, but it is only one side of his character. There are several occasions that the anime displays what goes on in his mind, portraying him as rational and possessing great situational awareness.
It is later revealed that his 'mad scientist' persona is largely a façade he wears in order to make life interesting for his dear childhood friend Mayuri and he tends to drop it if the situation becomes serious. He later drops his Chuunibyou façade completely upon witnessing Mayuri's multiple deaths, revealing a serious side of himself he has not shown for the first half of the series as he works hard to undo all the previous D-mails he has made - all in order to obtain the IBN 5100 and prevent Mayuri's death. As a result of going through dozens of time-leaps, he becomes rather cynical, depressed and frantic. He develops a guilt complex, believing himself to be responsible for everything that's happening and frequently blaming himself whenever something goes wrong, even when he had no control over it or couldn't possibly have seen it coming. An example is when he blamed himself for stopping Suzuha from leaving during the night of the storm, which resulted in the loss of her memory and her failure in finding the IBN 5100, despite Suzuha's insistence that the entire ordeal was her fault for not going straight back to 1975 and instead stopping in 2010 to find her father.
After Kurisu's death in Steins;Gate 0, he becomes ever the more miserable, to the point of experiencing panic attacks from references to Makise Kurisu and having to actively consume anxiety medications. Okabe had gradually wallowed in his own misery with his guilt complex weighing down on him, refusing to perform anymore time leaps even with the knowledge from Suzuha of World War III's inevitable occurrence within the Beta Attraction Field should he remain aloof to taking action. He had also abandoned the identity of Hououin Kyouma in its entirety, choosing to live as a normal university student, to great discomfort within his circle of friends. Over the course of the series, he regains the strong desire to see the future of the Lab Mems through to the end and returned to his former conduct; a notable feat is him having time-leaped over 3000 times backwards from 2036 to ensure it.
In the Suzuha Ending (of the visual novel), Okabe's personality becomes exceedingly warped and twisted, as a result of being forced to choose between saving Suzuha or Mayuri. Despite this, he soon returns to acting like his old self upon being confronted by Suzuha. He has seemed to develop feelings for Kurisu, along with Faris, Luka, and Mayuri, although these are determined depending on the route chosen in the visual novel. However, he openly displays his affections for Kurisu near the end of the story, regardless of the route chosen.
In the movie Load Region of Déjà vu, Okabe possess a strong distrust for time travel in general. After his experiences, he believes that no one can alter the past without unintended consequences and would rather be erased from the worldline completely over letting Kurisu use time travel to try and save him.
Rintaro lives an average life with his small group of friends until he creates the PhoneWave (name subject to change) with Itaru. His parents run a family business, and he has once gotten an eggplant for Christmas.
He is childhood friends with Mayuri Shiina. After the death of her grandmother, Mayrui entered a major depression and, fearing that she would go away (commit suicide), Rintaro embraced her and said the first thing that came to mind, which happened to be the ramblings of a mad scientist that he had seen on television. Proclaiming himself a mad-scientist, he stated that Mayuri was his hostage and as such, couldn't leave him. Mayuri accepted and this incident gave birth to his "Hououin Kyouma" persona.
In some Beta worldlines, as a child he encounters a woman at the train station who teaches him a song.
Rintaro went to the same high school as Itaru Hashida, though according to Itaru, they didn't actually become friends until their final year. The two of them, along with Mayuri would establish the Future Gadget Lab, a small research institution situated above a CRT store. It is an area where he and his fellow Lab Mems create "Future Gadgets for the betterment of mankind". He dubs himself Lab Mem 001 (the first to join the lab).
By the start of the story, He and Itaru Hashida are both students of Tokyo Denki University as engineering students.
- Main article: Steins;Gate/Plot
The Death of Kurisu Makise
In order to gather additional units for his college course, Rintaro attends a seminar being taught by Shouichi Makise about the fundamental theory behind creating a time machine. He arrives early, and upon entering the room of the lecture, the building is seemingly shaken by an earthquake. He runs upstairs and finds a satellite on the roof of the Akihabara Radio Tower. As Shouichi begins his seminar, Rintaro, a staunch believer of time machines, recognizes the core material on which the professor speaks and makes a commotion, accusing the professor of having plagiarized the idea from John Titor, who spoke of this theory 10 years prior. He is pulled out of the seminar and meets Makise Kurisu for the first time, though she insists on having seen him just 15 minutes ago.
Afterward, Rintaro talks to Mayuri about her Metal Upa, which she lost before they hear a scream come from upstairs. Rintaro rushes to the source of the sound to investigate and finds the body of Kurisu Makise in a pool of blood.
Rintaro is shaken by the incident, and he contacts his friend Itaru about it through a text message. Immediately after sending the text, the people in the street all disappear, and the satellite he saw earlier appears to have crashed into the roof of the Radio Tower.
He questions Mayuri about the apparent disappearance of the pedestrians, who seems to not have noticed. He later discovers that Itaru received the message, though 5 days earlier, and it is broken into 3 messages, and that Shouichi Makise's lecture was canceled.
While attending a lecture for credits that afternoon, he meets a perfectly unharmed Kurisu Makise. After that, he was in a state of shock, frequently touching Kurisu, who then accuses him of sexually harassing her. It was then that he realized that this was the real Kurisu.
John Titor and Future Gadget #8
Although he was certain that the events that he experienced did happen, he double-checks the occurrences on the Internet, coming up with the confirmation of what Itaru has told him. He would soon stumble upon John Titor, a time-traveling character famous for his discussions of the world in the year 2036, and this sparked his interest in knowing more about John Titor and his ideas about time travel.
Shortly after agreeing to let Kurisu join his lab (due to her curiosity about the experiment that Okabe and Daru are doing with the PhoneWave (name subject to change)), Okabe soon realizes that the PhoneWave (name subject to change) is actually a time machine. With the help of Kurisu, Okabe starts doing experiments with the PhoneWave (name subject to change) by using D-Mails (short for DeLorean Mail. This could be a reference to the famous "back to the future" movie series).
SERN and the IBN 5100
After stumbling upon Moeka, a shy woman that only communicates by her phone on the street of Akihabara, Okabe learns about the IBN 5100, an old and exceedingly rare PC that may be in Akihabara. Okabe also has Daru hack into SERN to find out some info related to the time machine. To his shock, SERN has been researching the time machine and already succeeded in making one. However, SERN did 14 experiments on humans, called the "Z program" and all humans that have been experimented on have already died and turned into a gel-like state and were found in different places in the past. Daru found an unknown database of SERN which even Daru cannot crack. Okabe decided to ask Titor about the code and found out that he needed the IBN 5100 in order to access SERN's secrets. Okabe starts searching for it and finds out that Faris' father once had an IBN 5100 and dedicated it to a shrine. He ultimately finds it at the Yagabashi Shrine and brings it back to the lab.
D-mails and Reading Steiner
Okabe starts doing experiments with the PhoneWave (name subject to change) by trying to send text messages (which the group agrees to call them D-mails) to the past. He learns that the experiments only work at a specific time of the day (10am to 6pm). Also, if the D-mails can actually affect the past, then the present will be altered and only Okabe can notice the change, as other members' memories have also been altered to fit the new timeline. He exchanges messages with John Titor, and learns about worldlines and Attractor Fields, and also that he has a special ability, which he can retain memories from before the worldline changes. He decides to call that ability Reading Steiner.
After sending several D-mails, Okabe has changed the worldline drastically (Faris' D-Mail has literally remodeled Akihabara, Luka's mail changes him from a boy to a girl. Also, the IBN 5100 is nowhere to be found due to the change of worldline). In the meantime, Kurisu is also working on the Time Leap machine, a modified version of the PhoneWave (name subject to change) that can send the user's memory to the past. Also, Okabe has been receiving threat mails from an unknown person, attached with gruesome images. The night of the day Kurisu completes the time leap machine, Mayuri's watch stops, much to her surprise. Soon, a group lead by Moeka attacks the lab, killing Mayuri in the process. With the help of Suzuha Amane, Okabe was able to use the time leap machine to travel back through time and save Mayuri. However, no matter how many times he tried, the result doesn't change: Mayuri still dies. It was then that Okabe begins to be terrified of Mayuri's death every time he sees Mayuri's watch stops. Falling into despair, Okabe confronts Kurisu for help. Kurisu advises Okabe to seek an explanation from Suzuha.
John Titor and the time machine
By confronting Suzuha after time leaping, Rintaro now learns that Suzuha is, in fact, John Titor. Suzuha travels from the year 2036 to 1975 to obtain the IBN 5100, but stops midway at 2010 to find her father, Barrel Titor, who is currently in Akihabara. Rintaro also learns more about the worldline and Attractor Field and the future of this Alpha worldline (SERN will rule the world with a dystopia, Rintaro becomes a terrorist leader, Kurisu is the mother of the time machine that enables SERN to complete world domination), and also that he cannot save Mayuri due to worldline convergence. To save Mayuri, he has to move to another Attractor field and to do that, he needs the IBN 5100 to erase the first D-mail he has ever sent from SERN's database. Rintaro and the other Lab Mems (consisting of Kurisu, Mayuri and Daru) agree to help Suzuha to fix the time machine (the machine previously thought to be a satellite lodged in the Radio Kaikan's rooftop), which is currently broken due to the rain a few days prior, as well as to find Suzuha's father. Daru succeeds in fixing the time machine, and Mayuri discovers that Suzuha's father is, in fact, Daru (although all the Lab Mems seem skeptical about it, Mayuri was able to show some undeniable proof, proving that Daru is the father of Suzuha). Suzuha was very happy, she bid farewell to the Lab Mems and go back to 1975 to obtain the IBN 5100 to give it to Rintaro (However, because the time machine was incomplete, she can only go back to the past, so if she manages to obtain the IBN 5100, she will have to wait 35 years to give it to Rintaro). Going back to the lab, Rintaro receives a letter from Mr. Braun, saying that it is a letter from an old friend of his. Realizing that it is a letter from Suzuha, Rintaro crumbles upon reading it. The time machine's repairs were incomplete, causing Suzuha to get amnesia and lost all of her memories when she went back to 1975. When she remembered her purpose for traveling to 1975, it was already too late to secure the IBN 5100. Suzuha fell into despair and committed suicide. Rintaro now realizes that he cannot obtain the IBN 5100 in this worldline, thus he sends another D-mail to prevent himself from the past from stopping Suzuha to leave Akihabara before the night of the rain so that Suzuha won't lose her memories when going back to 1975. Of course, doing so would make the other Lab Mems lose their memories regarding the time they had shared with Suzuha, except Rintaro with his Reading Steiner.
Retrieving the IBN 5100
After sending the D-mail, Rintaro still hasn't escaped from the Alpha Attractor Field, but because he did change the worldline, the Rounders' attack and Mayuri's death is delayed by 1 day. Now, he has to cancel all the D-mails he has sent in order to retrieve the IBN 5100. After some difficulties, Rintaro succeeds to cancel Feyris's and Luka's D-mail (which turns Akihabara back to "normal" (a city of Moe culture) and Luka was born a boy). The last D-mail he must cancel to get back to the worldline where he has the IBN 5100 is Moeka's D-mail.
With the little information he knows about her, Rintaro is able to find Moeka's apartment, but he also finds out that Moeka had committed suicide. Rintaro rushes back to the lab to time leap to when Moeka was still alive, but before he could do that, he realizes that someone is using the time leap machine(Nae). Unable to find out who that is, Rintaro decides to forget about it and time leap. He went to Moeka's apartment to find that she is in some kind of trauma because her boss, FB, seems to have abandoned her. After some struggling, Rintaro finally takes the phone from Moeka, and with the help of Kurisu (who is at the lab at the time), he sends a mail to cancel Moeka's D-mail. However, nothing happens as he realizes that the worldline hasn't changed (his Reading Steiner did not activate) while Moeka constantly pounds at the door. Soon he realizes that Moeka lied to him about the content of the D-mail. The real content is about the location of the IBN 5100. Once again, he sends a D-mail to cancel her D-mail, but still, nothing happens as the Moeka from the past seemed to ignore the mail and still searched for the IBN 5100. He then confronted Moeka, had another fight with her and was forced to kiss Moeka to silence her. He then gives Moeka back her phone, and offer her to help him to find FB, as he thinks that only FB's mail can cancel Moeka's D-mail.
After a stake-out in front of a locker (in which Moeka hid the IBN 5100), Rintaro and Moeka tailed many people who took the IBN 5100 and spent an all-nighter to find FB, which to their surprise, turn out to be Mr. Braun. After hearing the story from Rintaro about Amane Suzuha, Mr. Braun uses his gun to commit suicide. Rintaro then grabs his phone and runs out of the house. Rintaro is noticed by Kurisu (who has been watching outside the house) that after she heard the gunshot, someone in the house jumped out of the window and ran away. Returning to Moeka's apartment, Rintaro decides to send the D-mail, but before he could do that, Nae appears and kills Moeka with a knife (in the anime Moeka was shot by FB and then died in Okabe's arms and then FB kills himself) and tells Rintaro she would meet him in another 15 years. Shocked by the new revelation, Rintaro postpones sending his D-mail to time leap again to learn the reason why Nae did it (this is optional, the player can choose to send the D-mail instead of time leaping, the outcome won't be any different, just that Rintaro won't know anything about why Nae killed Moeka). This time, Rintaro waits outside of the house (FB will definitely die due to worldline convergence). After the gunshot, Nae leaps through the window, Rintaro chases her and eventually catches up to her. He now learns that this is not the Nae he knows but in fact the Nae from 15 years in the future, who'll actually become a Rounder. She is the one who captures Rintaro and tortures him to death, and then takes the time leap machine to travel to the past to exact revenge against Moeka and Rintaro (though she cannot kill Rintaro because doing so would result in a paradox). Upon learning the truth, Okabe finally decides to send his D-mail and returns to the worldline in which he obtained the IBN 5100.
Struggle and Confession
Rintaro, after undoing Moeka's D-mail, notices that if he cracked SERN's Database and delete the first D-mail by using the IBN 5100 he'll end up in a world where Kurisu died at Radio Kaikan. Therefore he refuses hacking SERN to delete the first D-mail. He struggles to find a way to save both Mayuri and Kurisu, but all is in vain. When Kurisu asks him why he didn't crack the first D-mail, he tells her the truth about her death. Kurisu doesn't care if she dies and urges him to save Mayuri. Rintaro then confesses his love for her. She kisses Rintaro (and he demands another one from her after the first kiss). Rintaro finally decides to sacrifice Kurisu and return to the original Attractor Field he was in.
Now in the original worldline, still reeling in devastation after Kurisu's loss, Rintaro receives a phone call from Amane Suzuha, who offers to meet him on the roof of Radio Kaikan. When Rintaro gets there Suzuha tells him that they needed to prevent Kurisu's death because it somehow stirred up WW3. However, when they attempt to do this, the operation ends in disaster when Rintaro tries to stab the culprit with a knife but stabbed Kurisu instead. The force was so strong that the knife pierced the skin and penetrated the flesh, all the way to the bone. Okabe felt that. He was then left with a dying Kurisu in his hands. Kurisu then apologizes for letting Okabe get involved in her murder, saying "I'm sorry for dragging a stranger like you into this." before finally collapsing onto him, staining his outfit and filling his soul with grief.
After returning to their time, Rintaro was devastated, repeatedly saying that "I killed Kurisu" and wanted to take an eternal slumber.
Mayuri attempts to comfort him, convincing Suzuha that he needs to come to his own conclusion.
After 6 months, Rintaro still has not gotten over Kurisu's death. Having given up his Houoin Kyouma persona entirely, he has stopped visiting the Future Gadget lab and has dedicated himself to being a completely normal university student. While at a conference, he encounters Alexis Leskinen and Maho Hiyajo, and ends up revealing his connection to Kurisu to them, though leaving out all the elements of time travel. Leskinin deems Rintaro to be a good test subject for Amadeus, an in-development artificial intelligence based on Kurisu's brain patterns. Rintaro agrees and while initially hesitant, quickly begins growing closer to Amadeus. Maho, noticing this decides to separate Rintaro from the program, reminding him that Amadeus is not Kurisu, so it would be bad if he developed feelings for it.
Back to the Alpha Attractor Field
Eventually, Okabe finds himself back in the Alpha Attractor Field for seemingly no reason. He encounters Daru, who is suprised to see him out and the two go to May Queen. When Rintaro wonders where Mayuri is, the room grows quiet with Daru telling Rintaro that that was insensitive. Rintaro asks Daru what he is talking about and Daru explains that rintaro (in this wordline) didn't go through with erasing the first D-Mai and ended up destroying the Phone Wave and Time Leap machine, allowing Mayuri to die and forcing himself to accept her death. Disturbed by this revelation, Rintaro desperately runs back to the lab where he encounters Kurisu. Upon seeing Kurisu, he emotionally embraces her. Kurisu quickly realizes that he is from another worldline and the two compare histories, with Kurisu explaining that after Mayuri's death, blaming himself for the death of his childhood friend, Okabe entered a depression, dropping his Hyouoin Kyouma persona, dropping out of college, avoiding the Future gadget lab, and not interacting with any of this friends. She realizing that the key difference is that in the current worldline, she unintentionally shattered Okabe's resolve by confessing to him before he could erase the first d-mail. She hypothesizes that the proper d-mail could fix the situation and and reveals that she had rebuilt the phonewave. While initially hesitant about changing the worldline and indirectly killing Kurisu again, he is convinced by Kurisu who doesn't want Okabe to go through the depression she has seen already seen him experience. Rintaro ends up agreeing and they send a d-mail to Kurisu in the past, which distracts her just long enough for Rintaro to undo the first d-mail.
After returning to the Beta Attractor Feild, Okabe wakes up in the hospital, learning that he and several others had seemingly passed out from pneumonia. Several days later, Rintaro receives a call from Luka stating that the shrine was looking after an amnesia young woman and Luka wanted to introduce her to the lab, hoping they could help her. Luka brings her over and the woman is revealed to be Kagari, the girl Suzuha had gone back in time with and lost in 1998, though significantly older. Upon seeing Mayuri, Kagari regains her memories prior to her disappearance, but nothing more recent.
While Kagari stays with them, Kagari sings a song taught to her by the future Mayuri and Rintaro decides to track the origin of the song down in order try and learn more about her past. It is revealed that Mayuri was taught the song by Yuki, who learned it from Rintaro's mother who overheard Rintaro singing it, which Rintaro doesn't recall. It is revealed in a flashback that, as a child Rintaro was actually taught the song by Kagari while at the train station. After Kagari disappears the group spends the next 6 months trying to locate her, with no luck.
Prelude to WWIII
Eventually Maho and Leskinin return to Japan and Maho reveals that she possesses Kurisu's old laptop which she had been trying to get into. She tells Okabe that there was a hacker in the area who agreed to try and unlock it, only for that hacker to later be revealed to be Daru. Before Daru can begin hacking the laptop, Rintaro notices several suspicious individuals and convinces Maho and Daru to exit out the back. After exiting into an alley, the group is cornered by a group of masked individuals demanding the laptop. Before they can give the laptop over, another group arrives and opens fire. While Rintaro, Daru and Maho are unharmed, the laptop is destroyed and the first group is forced to retreat, with the second leaving immediately after. Maho asks what's going on and Rintaro explains his history of time travel to her in an attempt to get her to stop trying to dig up Kurisu's notes.
Believing the rounder might have been involved, Rintaro confronts Yugo. After it is clear that Okabe knows more then he should and Yugo confirms that he and Nae aren't in any danger, he drops the pretenses and tells Okabe that he doesn't know what he's talking about.
After learning that Kagari has reappeared and seemingly been brainwashed, Rintarou and Moeka track down the lab where she had been kept, developing a stronger understanding of what happened to her.
After learning that Mayuri and Suzuha were planning one last attempt to go back in time in order to convince Okabe to save Kurisu, he became desperate to stop them. He head to Radio Kaikan in order to stop them, but is confronted by Alexis Leskinin, who reveals his true actions and intentions to Okabe. Okabe manages to get past him and get to the roof of the building, but he is unable to convince them to stop. However, before they can time travel, the time machine is destroyed along with Suzuha and Mayuri. Devastated, returns to the future gadget lab where Daru and Maho reveal that they had actually been attempting to rebuild the time leap machine. Rintaro manages to use is to send his mind back to before the time machine exploded, but he is unbale to prevent its destruction. Okabe uses the time leap machine again in an attempt to prevent Suzuha and Mayuri's deaths.
Stuck in the Future
An error with the machine causes Rintaro's consciousness to be thrown 25 ears into the future to the year 2036. Rintaro finds himself emaciated in a hospital bed. Managed to pull himself out of the building, he is confronted by Suzuha, who, realizing who his is, saves him from some military soldiers. She takes him to Daru who reveals that the Okabe of that worldline ha been captured by Stratfor agents in 2025 and tortured into a vegetable-like state. Afterwards he had been rescued and Daru lied about his death to keep him off of Strafor's radar. while Amadeus was monitoring him, Luka and Faris were in charge of taking care of his physical needs. After Luka and Faris get aught in a trap lying to Luka's death, Rintaro resolves himself to return to the past and prevent this horrible future. Understanding that the time machine is not yet usable, Okabe instead decides to use the time leap machine despite knowing that because of the machine's limited jumping ability, he would need to jump over 3,000 times. Each time he wakes up in his comatose body, he explains the situation to Amadeus who contacts Daru and the others. After going back to before his torture, he uses his knowledge of the future to prevent him capture and ensure that he could continue to time leap.
Saving the Future
He eventually returns to his proper time, but is still unable to prevent the destruction of the time machine. Time leaping once more, he comes up with a plan, getting help from the rounders to fight Stratfor & Durpa's forces so he can let Mayuri and Suzuha go. This works, and Rintaro is so overjoyed that he managed to prevent the nightmarish future that he experienced that he revives his Houoin Kyouma persona.
14 years later in 2025, Okabe and the rest of Valkyrie send a d-mail to his younger self explained Operation Skuld. He then uses the prototype time machine to rescue Suzuha and Mayuri who where stuck in the distant future.
Suprisingly, Mayuri slaps his face. He then awaken from his delusions and receives a message from himself in the future, telling him that the way to save Kurisu without altering the events that led to him developing a time machine is to fool his past self into believing Kurisu had been killed and allowing Mayuri's Metal Upa to not be detected by the Metal detector in the airport and let the files that was stolen by Shouichi Makise burn down in the accident, thus achieving the final divergence value that's larger than 1 (1.048596), which he dubs the 'Steins Gate'. His Future self dubs this mission as 'Operation Skuld'. Rintaro planned on doing this by knocking her out with a taser and using the fake blood in Future Gadget #6 (the lightsaber from Spark Wars.
When Rintaro returns to the past, he obtained the Metal Upa first before his past self does. Mayuri will then instead receive an ordinary green Upa, lose it, and have it picked up by Kurisu Makise. Rintaro soon realizes that the fake blood he brought dried up. Without much choice, Rintaro risks his own life by letting himself get stabbed by Shouichi Makise, and then using his own blood to recreate the scene where he saw Kurisu lying unconscious on a pool of blood, in order to save her. Kurisu witnessed it and called for help. But Okabe then tasers her and leaves her lying in the pool of his blood, before saying "farewell" to Kurisu and talk about his past self (the next 3 weeks will only be a mere 3 weeks to others, but, for you, it was the time you spent with Kurisu). Suzuha calls Okarin stupid for doing that, because he risked dying of his injuries and exposing himself to his past self but Okabe retorts, stating that the mission was successful, and he fulfilled all of the objectives: create a fake crime scene with Kurisu bleeding, and fool his past self. Rintaro returns to his time.
He was hospitalized for about a month due to his wound and around September 2010, he got out of the hospital, consequently obtaining 8 LabMem badges which were just finished. Rintaro visits Yanabayashi Shrine to appoint Luka Urushibara as LabMem #006 and gives him the LabMem badge, then visits Mayqueen to appoint Faris as LabMem #007 and gives her the LabMem badge as well.
As he was about to go upstairs to the Lab, he finds out that Moeka works as a Part-Timer in the CRT workshop. He then gives her the LabMem badge and appoints her as LabMem #005.
In the Visual Novel it continues and shows Rintaro heading into the Lab and finds Mayuri and Itaru inside, and gives them their respective LabMem Badges, while in the Anime, Mayuri was not around since she was looking for Rintaro who was released from the hospital. He then puts another LabMem Badge in a box and tells Itaru that the 8th Member will appear 7 years later, and for Itaru it was an inescapable fate.
Rintaro goes back out to the streets of Akihabara, carrying 2 LabMem badges. One is for himself, LabMem #001, and the other one is for LabMem #004, Kurisu. Okabe reflects that it will never reach its owner since Kurisu in this worldline has no memories of the 3 weeks she spent with Rintaro in the Alpha worldline.
A bit saddened by the realization, he walks through a crowd of Akihabara, when someone familiar passes by him. He stops and turns around, not really believing what he'd seen. The person turns out to be Kurisu. She smiled thankfully and remarks that she was afraid of never being able to see him again and would forever be unable to thank him for saving her life.
Rintaro who becomes too emotional puts up his Chuunibyou act and pulls out his phone. He tells the phone that he's unsure of why he was able to meet her again and states that he would accept the task of protecting her in the name of Steins;Gate.
In a slip of tongue, he calls Kurisu by the nickname he used in other worldlines, Christina. Kurisu replies to him by stating that she isn't Christina, nor his Assistant. Both were surprised, and Kurisu reveals that she had just acted on instinct. Okabe reflects that the Kurisu in this worldline should not have known about the nicknames he gave her in other worldlines. But then he comes to a realization, that Reading Steiner, exists in every single human. All they need is a little push and they would remember. Rintaro then welcomes her and appoints her as his Assistant once more before giving her the LabMem badge he had. Rintaro continued living in this Steins;Gate worldline happily with both Kurisu and Mayuri safe and sound.
Trip to America (Anime Only)
Eight months later, Future Lab Mems with the exception of Moeka goes on a trip to America. However, after seeing a woman who resembles Suzuha, in a moment of rashness, he follows her to a truck stop in the middle of nowhere. After learning that she wasnt Suzuha, he is unable to make the return trip with only a dead-battery phone and 67 cents. Afterward, Kurisu came to his rescue, only to be stuck in the same situation as him due to the car running out of fuel. Stuck in the middle of a deserted highway with no one in sight, Okabe then confesses his love to Kurisu. Standing up, Kurisu asks Okabe to close his eyes as with the other worldline, finally completing the choice of Steins;Gate.
Near Erasure from Steins Gate (Anime Only)
Kurisu visits Japan and meets up with the Future Gadget Lab. Throughout the day, Rintaro get flashes of his deaths on other worldlines, but is unable to explain them. That night they throw a party for her where Okabe seemingly disappears for a moment with only Kurisu noticing. Kurisu later gets drunk and confronts Okabe on not contacting her after what happened in America.
The next day, Okabe and Kurisu have a discussion at the laundromat where Okabe disappears and Kurisu finds herself unable to remember him at all. After Kurisu remembers him thanks to his lab coat and confronts Suzuha Rintaro reappears, telling her not to use time travel even if it means that he ceases to exist. Kurisu refuses and does end up going back in time and giving a younger Okabe the idea of Hououin Kyouma before kissing him, cementing his place in the worldline. The movie ends with Kurisu returning to the present and her and Okabe joking about her taking his first kiss.
The Kidnapping of Nae Tennouji
In December in Akihabara, Rintaro Okabe is suffering from PTSD due to the events of the summer when he receives a letter from Kurisu Makise on December 14th, his birthday. However, things start to go wrong when Nae Tennouji suddenly goes missing on Christmas.
The story begins with Okabe putting on a chuunibyou act because things are going too well in this Worldline (to which the others are either unaware or unbelieving of it). He receives an email anticipated from Kurisu and quick opens his inbox, though to his utter disappointment, it is spam mail.
Hashida mentions how "mad" he is about Okabe being a "Riajuu" compared to himself; an otaku. Mr. Braun barges in to ask that the group of 3 watch his daughter as he and Moeka go to do "business" in another area. Over the course of their supervision for Nae, they consistently try to cheer her up or get her excited, though none of it works very well. Urushibara joins their group which Nae quickly attaches to and Okabe and others head off to walk around in Akibara.
Okabe begins experiencing PTSD from the time when he was attacked by Nae's 2025 vengeful counterpart (this did not happen in the anime.) after she stares at him with a blank expression before looking away, believing she frowned. Infering she was thinking of something sinister he wraps his scarf around him. They encountered a mini-festival where Okabe, Mayuri, and Ruka took pictures before hearing Nae's minor screams after being touched by a "suspicious ugly guy." Okabe goes to confront the man before a Santa from earlier blocks his way. Though as it turns out; the Santa is on Okabe's side and stops the man.
The group meets Faris later in the day and asks her if there are any interesting places near the cafe, she mentions a gamecentre and they make their way there. Hashida challenges Nae to a match in any game she wants, surprisingly; she picks a fighting game. Okabe begins over examining Nae over her one handed catch of the yen he threw to her to test if what he was seeing was real or not. Hashida picks a fat character that Urushibara mentions is similar to Daru's own look. Hashida was extremely confident that he would one-sidedly destroy Nae. It proved false. Nae absolutely obliterates him and mentions that she simply felt her body move on it's own during that, to which Okabe panics and evaluates how she gouged Daru's characters flesh just like she did before to himself but is reminded that everyone has some tiny form of Reading Steiner present in them.
Okabe realizes that his tensed body has caused him to have urgency to use the restroom so he quickly rushes off. He looks through his emails again as to check if Kurisu had sent him an email. He reopens her last email from 10 days ago that had some light words of blessing and talked about how busy her research was becoming. However, an anxiety bloated within his body and his Hououin Kyouma self laughed at him; telling him he was nowhere good enough for a genius girl with a bright future ahead. Okabe suppresses these thoughts and reveals to himself that he simply has the Hououin Kyouma persona no longer for Mayuri, but rather himself. For the sake of keeping his sanity and as a reminder that he is safe in the Steins Gate. He finishes his business in the restroom and exits but is greeted by Nae Tennouji.
Asking if she need go to the restroom herself and exclaims its location Nae quickly responds with, "Hey, Uncle Okarin." As he was about to correct her, she replies again. "I'll kill you. Okabe Rintaro." Okarin quickly falls into disarray and dreads in his mind what is happening, though hastly comes to the conclusion he is simply tired. Okabe and Nae converse about how he looked throughout the day: Tired and depressed. Nae mentions that he has the same eyes her father has whenever he thinks of her mom. Okabe later asks Nae how she was so great at that fight game though she brushes it off as she practices and plays it plentiful with her friends. Finishing their conversing he redirects Nae to rejoin with the group.
Okabe rejoins his group, however Nae is nowhere in sight. It becomes a major problem after an hour she does not appear when called to the front counter. Urushibara receives a call from Nae. They ask for her location where she vaguely describes it but is subdued by a man and the call is ended. Before the call was ended Nae mentioned a symbol that looked similar to a 6 and 9 corresponding to one-another. Hashida is unable to find her with just this much information but Mayuri quickly cracks it by thinking in a more visual way. The 6 and 9 represent the Yin Yang Symbol. Though this alone was still not enough information and Okabe was about to call it off. Until, an illusion of Kurisu to him to stand up and keep going, not to give up. Through the help of Faris, who's tweet sent roars through social media thanks to her influence, viral attackers managed to crack the location of the kidnapper.
Okabe and Hashida battle the massive kidnapper and subdue him with Luka carrying his "Demon Sword Samidare" and Mayuri with the "Cylalume Saber". As it turns out, the kidnapper was the foreign Santa from earlier of that protected Nae. He had her dress as Rai-Net characters and take photos of her. As Okabe was in deep thought, he heard the large otaku's groans and turned around to see Nae kicking the man in the crotch 1, 2, 3 times.... and more. He is taken by the police and the situation is handled.
The Lab Mems rejoin one another back in the apartment and have a small buffet for Nae's sake. Mr. Braun returns after having several missed calls but Nae dismisses it as simply wanting to hear her dad. The lab won over his uneasiness. The day is finished.
Later, Okabe is walking outside and greeted by Mayuri, when he receives an email from Makise Kurisu, with a post script stating that she sent a letter to him. However, when he rushed back to his mailbox, there was nothing.
Note: Spoilers for Robotics;Notes DaSH follow.
As of 2020, Okabe resides in the United States and researches at Viktor Chondria University alongside Kurisu and Maho Hiyajo. Hashida mentions that after Okabe came up with the "Worldline Theory", he changed significantly and migrated to study with known geniuses. During that time, Okabe reinvented his divergence meter to watch over the Worldline; however what it has revealed recently shows that The Steins Gate is in jeopardy. The meter will display 1.048596 as it should, but occasionally twitches, changes numbers, or glitches. This worried him enough to contact Hashida, by which Hashida mentions Okabe never goes out of his way to make calls or message. He relayed one message to Hashida before calling him: "The Worldline is wavering..."
- "Consider, can the universe be justifiably called infinite? Doubtful. It may not have a discernible end, but it had a beginning and its component parts definitely have a limited cosmological shelf-life. Splitting hairs or not, if history tells us anything, it's that scientists often make very poor poets. We're all just a ship of fools chasing phantoms, heedless of what really underwrites natural law." -Okabe's opening monologue (English dub)
- "The universe has a beginning, but no end. — Infinite. The stars, too, have a beginning, but their own power leads to their destruction. — Finite. History dictates that it is the wise who are most foolish. One could call this a final warning from God, to those who can still resist." -Okabe's opening monologue
- "It's the choice of Steins Gate." -Okabe's catchphrase.
- "I'm the great mad scientist, Hououin Kyouma!"
- "Perverted Genius Girl!" -Okabe to Kurisu Makise.
- "Sorry, The Zombie~~" -Okabe to Kurisu.
- "Let's hear what the genius thought!" -Okabe to Kurisu.
- "Daru is like the universe — constantly expanding." — Okabe about Itaru Hashida
- "Theories are nothing more than words. Accept what you have seen!" -Okabe to Kurisu.
- "I won't let you go. I won't let anyone take you. You're my hostage now. My guinea pig! There is no escaping me! Muhaha, muhahaha!" -Okabe to Mayuri Shiina.
- "Uhh... Hey mister, I am mad scientist. It's so COOOOL! Sonuvabitch." -Okabe to badge maker, trying to speak English.
- "It's an intellectual drink for the chosen ones." -Okabe about Dr. Pepper.
- "I would say the person with the perverted imagination is the pervert." -Okabe to Kurisu.
- "This is Luka Urushibara. The 'son' of this shrine's chief priest. Yes, a son. No matter how you look at him, he looks like a lovely girl, but... he's a guy. ...His voice and behavior makes him look like a female. Or more like, more feminine than a female. But he's a guy. Taller than Mayuri, yet oh so slender... But he's a guy. Looks stunning in shrine maiden clothing. But he's a guy. He's holding a broom, so I'm guessing that he was in the middle of cleaning. But he's a guy. It's so hot, even though it's almost evening. But he's a guy. Hell, cicadas won't shut up. But he's a guy."-Okabe about Luka Urushibara.
- "Is this the choice of Steins Gate. No, get out of your damn head! None of that stuff is real! Not Steins Gate, not the Organization, none of it!" - Okabe to himself
- "It's all my fault. From start to finish, it's my fault. I'm the one who told Daru to hack into SERN. I'm the one whose stupid idea it was to build a time machine to begin with and the one who brought Moeka into her lives. I'm the reason that Mayuri [sobs]" - Okabe to Kurisu.
- "You, on the other side of the monitor, with the dumb expression!" - Okabe to the Alpaca-man software.
- "Because I'm from the goddamn future!" - Okabe to Moeka.
- "No one knows what the future holds, that's why its potential is infinite. Just like what this reunion demonstrated." - Okabe to Kurisu during their reunion in the Steins;Gate worldline
- "Alright! From now on, I am Mommy Uncle Okarin!" - Okabe to Nae Tennouji
- "I am mad scientist. United States, Chaos, and Invade!" - Okabe to Airport Worker, OVA
- "Seinem das Jede." - Okabe to Kurisu, Steins;Gate QNP Special
- "How much time have I lived through? Through how many world have I travelled? Numbers too great to count. So much that the sky and the stars became blurs. But no matter what, I always had you there with me. I always had your smile to reassure me. "I'm fine, so...". On that day, you smiled gently and left me with those words. An event so very, very long ago that it almost feels like a lifetime has passed. Those words rest with me even now. Not once have they faded from my mind. I knew all along. That was your gentle lie to me. A lie far too slefless. All so that I could continue onwards. I could tell even then that you were lying, but I clung to your words regardless. I placed everything on them. Night spent wailing with grief. Winters spent writhing in agony. No matter how the seasons passed, no matter how blessed I was by people's kindness, there forever remained one regret that would gnaw away at the back of my mind. Of course, I already know. I know that you'd never blame me for what happened. Even so, Within that endlessly repeating time, The weight of the sin that I bore... It never faded, not even for a second. But now... Now, having crossed through those innumerable worlds, I've finally become aware of their importance. Wandering blindly in the dark, Having lost my bearings, on a journey with an unknown destination... Those who stood by me and supported me through it all. My precious friends... And of course, you. Never fading, no matter how much time passed. My feelings towards you. Because everyone was always there for me, because "she" gave me a push on the back, and because "you" were right here with me too. These are the reasons that I'm able to move onwards once more. The "you" living on inside my heart gives me courage even now. "Pull yourself together already." I'm sure you'd be saying something like that right about now. I wouldn't blame you. After all, I feel the same way. But you need to understand. I can't bring myself to let go of those memories. All the tears that were shed, the blood that was bled, all those feelings left unsaid. I wasn't able to let go of a single thing... That's why I've decided to aim for it once more. Yes. The "Gate". The "Gate" which exists in the gap between past and future, between miracles and fate. It may well take me another few lifetimes in order to achieve this. It may be that I need to traverse countless more worlds. But I do not care. There's not an iota of hesitation left within me. I've steeled myself. No matter how many times it takes, no matter how many worlds I cross. I'll make it there for sure. I'll be able to "begin" once again. That is my... That is our choice. So I don't need your gentle lies anymore. Please, wait for me. Until the day that we can meet once more. Until the day that begins our new "past," and our new "future" ." - Monologue Okabe in 2025, Drama CD Lyra of the New Dawn.
- In the Gamma worldline, Rintaro is a collaborator of SERN, member of the Committee of 300 and becomes the dictator Hououin Kyouma, ruling over Japan with an iron fist.
- Rintaro loves to drink Dr. Pepper but in the Gamma worldline, his favorite drink is Mountain Dew.
- The reason Rintaro barely calls Kurisu Makise by her real name, but instead with the various nicknames, is because he was too embarrassed to call her by her real name.
- The actions of the Committee of 300 of the Steins Gate worldline fit Okabe's delusions almost to the letter.
- Rintaro claims he has an IQ of 170. For reference, 145 is considered the genius level of intelligence.
- Kurisu drank a can of alcoholic beer once, and was drunk before she could finish it, causing Okabe heaps of trouble. During the time she was drunk, she pushed Okabe downstairs and asked him to hug her and spend some quality time together. Okabe however, was too shy to even reply. Kurisu then hugs him even tighter and both of them fell down a flock of stairs, giving both of them a headache.
- In the future of the Alpha worldline, Okabe became the leader of the resistance against SERN's rule, and was known as an international terrorist (in the side story ""The Distant Valhalla,"" it's revealed that SERN released Okabe and Daru so that they could found the resistance, thus completing the cycle of fate). Okabe's in the Beta attractor field got captured by SERN's Rounder unit in 2025 and was tortured to the point when his will to live is broken, and left braindead.
- In the events of Deja Vu, Kurisu Makise is the one who gives Okabe the backstory and name of Hououin Kyouma.
- His catchphrase, "El Psy Kongroo" means something like "The Mind Agrees" or "The Mind is Congruous" and is supposed to be Latin, but the grammar is not correct.
- Rintaro Okabe is also playable in the game #COMPASS.
- Rintaro calls his favorite order at Kitchen Jiro "Mad Menchi Katsu Curry" which is curry with two pieces of menchi katsu as toppings.
- The name Rintaro means "ethics, companion" (倫) (rin), "thick, big, great" (太) (ta) and "son" (郎) (ro).
- Rintaro's surname Okabe means "ridge, hill" (岡) (oka) and "part, department, category, section" (部) (be).
- Hououin means "phoenix/phoenix bird" (鳳凰) (houou) and "hospital, institution/Inst., temple, mansion, school" (院) (in).
- Kyouma means "bad, misfortune/mischance/miscarriage, ill luck/unluck, fail, muff, overshoot, fiasco, baffle, calamity, affliction, disaster, catastrophe, cancer, plague, distress, harm, poor crop/poor harvest/scanty harvest/lean harvest" (凶) (kyou) and "real, genuine" (真) (ma).