Kagari Shiina

Kagari Shiina (椎名 かがり, Shiina Kagari) is one of the characters of Steins;Gate 0. She is a war orphan and the adopted daughter of Mayuri Shiina in 2036 in the Beta Attractor Field. She was stranded in the year 1998 after having run away from Suzuha Amane, who she had time travelled with to stop the Y2K problem.

Appearance
Kagari is a pale-skinned girl with long red hair, blue eyes and slender build. Although her similarities with Kurisu Makise are initially noted by Rintaro Okabe, there is no known connection between the two.

Personality
As a child, Kagari deeply cares for and idolizes Mayuri. Her most prized possession is an Upa Keychain Mayuri left to her. After being forced to use the time machine, her biggest fear was that changing the worldline would result in her never meeting Mayuri. As a result of her brainwashing, she prioritizes Leskinen's orders almost instinctively. She hears his voice in her head almost constantly, believing it to be "the Voice of God", and the only thing that can convince her to go against these orders is Mayuri and in the Recursive Mother Goose ending, the voice disappears entirely.

When she has amnesia, she was a kind meek woman. After regaining her memories, her affection for Mayuri returns, but even though she cant remember anything past age 10, she acts her age. Though she still refers to Mayuri as "Mommy". She shows signs of PTSD, sometimes suddenly screaming and begging her mother to save her.

As Kurisu's memories begin to overlap with Kagari's, she becomes increasingly worried about disappearing. She starts panicking at the prospect that "Kagari" would be replaced by Kurisu. That being said, she still wanted to know more about Kurisu, asking Okabe to take her to where he met her.

After her experimentation and "training" at the hands of Stratfor, Kagari is shown to be ruthless, calculating, and cold, keeping Moeka at death's door many months in order to assure her loyalty and killing those who get in her way. However, this breaks away when Mayuri is involved. She is incredibly unstable, jumping between her admiration for Mayuri and the orders given to her by the "Voice of God". She desperately wants Mayuri to treat her as she did in the future, and upon seeing Mayuri injured, she enters a berserk rage with the intent of slaughtering whoever is responsible.

In the Vega and Altair route, Kagari acknowledges that she fell in love with Daru while posing as Yuki.

Background
Due to the death of her parents during World War III in the Beta Attractor Field, Kagari became an orphan at a very young age. Since the registers of her family had been lost during the war, her true name was lost. She first met Mayuri Shiina during the year 2028 as she was working at a children's orphanage, and was given custody of the girl.

As the connection between the two grew, Mayuri went to eventually adopt Kagari in the year 2032, becoming her new mother and giving her her new name.

However, during the time Kagari spent in the orphanage, she was a victim of numerous experiments lead by Alexis Leskinen, who was trying to test Amadeus' capabilities as military weaponry, under the pretense that she was being treated of PTSD.

In the year 2036, Kagari was forced to travel back to the past alongside Suzuha Amane to escape an incoming attack. However, after they stopped in 1998 to stop the Y2K problem in 2000, Kagari's fear to lose her mother due to the worldline change caused her brainwashing to activate, resulting in her attacking Suzuha and running away. After that, she went on to contact Alexis Leskinen of that time and explained details about the future to him. She was then taken by Stratfor to further experiment with her and given the codename "K6205", a reference to Mozart's The Magic Flute. Before escaping, she was kept in a building close to Tokyo and missed Mayuri so dearly that she wrote "Mommy" and "I miss you" in what appears to be blood everywhere in a particular room.

At one point, she escaped and met a young Okabe at a train station, teaching him a song. However, she was recaptured and this event was forgotten.

Stray Sheep
In some worldlines, she would eventually escape again in 2010, but this time suffering from complete amnesia. She was taken in by a temple, but believing that it was bad for the monks to be in the presence of a young woman, she was left in the care of Yanagibayashi Shrine. Believing Rintaro might be able to help her, Luka contacts him, but is unable to fully explain the situation. He later brings Kagari to the Future Gadget Lab and upon seeing Mayuri, memories of her childhood return to her, leaving her as a 22 year old with the mental state of a 10 year old.

Gehenna Stigma
Kagari finds Maho after the girl tells Mayuri the truth about her numerous deaths. She briefly threatens Maho for hurting Mayuri, but leaves upon realizing that Mayuri was in danger.

Later, Maho finds Kagari at Radio Kaikan, with the girl being depressed following Mayuri's apparent death. Maho convinces her that they need to try and save Okabe. Once they get Okabe from Amadeus, they lead an assault on the facility, with Kagari dying in the battle.

Vega and Altair
After Moeka is betrayed by SERN, Kagari saves her life. Kagari keeps Moeka locked in her apartment and leaves her injuries untreated for five months, then, when Moeka is at her breaking point, Kagari gives Moeka a new phone which Kagari uses to send her messages posing as FB. Kagari then begins treating her injuries.

First Iteration
Later on, when Mayuri and Suzuha attempt to use the time machine, they are intercepted by Stratfor, resulting in a Mayuri being injured. Kagari then arrives and, noticing Mayuri's injury, begins brutally slaughtering the Stratfor agents with a pair of cleavers much to Mayuri's and Suzuha's horror. While Kagari does manage to kill all the agents, she is severely injured, including multiple gunshot wounds and and even having her hand severed. She then attempts to crawl towards Mayuri but is distraught over Mayuri's apparent fear of her. Losing the remainder of her strength, she is caught by Okabe who removes her helmet, revealing Yuki's face. Realizing that Kagari does not want Mayuri to see her face, Okabe tells Suzuha to focus on Mayuri while he looks after her. Kagari explains that she had been impersonating Yuki since she met Mayuri and Daru and the real Yuki was on an exchange trip to Europe and would not meet Daru for another year. She then states that the real Yuki would definitely fall in love with Daru like she did before dying in Okabe's arms. Not wanting to tell Mayuri and Suzha of Kagari's death, Okabe lies, saying that he plans to take her to the hospital.

When the time machine is seemingly destroyed, Okabe is forced to leave her body behind in order to escape.

Second Iteration
After Okabe time leaps to before the war, he manages to slow down the Stratfor forces and reach the rooftop before they arrive. Kagari then appears, shoots Okabe in the leg and attempts to prevent Mayuri and Suzuha from leaving. Okabe, despite being outmatched, manages to hold her back long enough for Mayuri and Suzuha to leave. A distraught Kagari, once again feeling abandoned points her gun at Okabe, but Okabe manages to talk her down and convince her that Mayuri and Suzha went to save the world, despite the "Voice of God" telling her otherwise. Kagari is then shot by Moeka, who had seen through her deception. Then, as before, Kagari dies in Okabe's arms.

Runaway of the Free Particles
In the wordline shown in the Drama CD "Runaway of the Free Particles", Kagari Okabe is Rintaro's adoptive daughter from 2036. Believing that her mother does not care about her because she is not her biological daughter, Kagari runs away from home, using a time machine to go back to 2011 where she meets the Future Gadget Lab. While Suzuha tries to being her back, the lab members dote on and spoil her throughout the day, with several of the girls being especially so after she notes that her mother used to be very gentle. Later, Kurisu helps remind her that her mother actually does love her and she agrees to go back with Suzuha.

Trivia

 * As with other elements of Steins;Gate 0, Kagari was first introduced in the Epigraph Trilogy.
 * The song that Kagari teaches Rintaro was taught to her by Mayuri who learned it from Yuki who learned it from Rintaro's mother who learned it from younger Rintaro himself and who then learned it from Kagari from the past. This creates a situation resembling a causal loop with the song seemingly not having a proper origin.
 * While it resembles a causal loop, those do not exist in Steins;Gate due to how time travel is explained in the series. The song's true origin is most likely a prior Beta wordline that was overwritten after Kagari time-travelled.
 * One of the possible origins for the song is the music box gifted to Maho during the Vega and Altair branch of the Visual Novel.
 * Kagari has been assigned the lab number 010.
 * Kagari is somewhat claustrophobic, being unable to stay in confined spaces for long periods of time.
 * Kagari only appears to replace Yuki in the Vega and Altair ending as they remain as separate characters in nearly every other ending.
 * The Gehenna Stigma ending is the only ending where it is left ambiguous as she dies off screen, so her face is never seen.

Etymology

 * The name Kagari was given to her by Mayuri Shiina - a reference to "kagaribi（篝火?)", meaning bonfire -, with the wish that Kagari would be a shining light to everyone no matter how dark the worldline was.
 * Kagari's surname Shiina means "oak, mallet" (椎) (shii) and "name, noted, distinguished, reputation" (名) (na).