Suzuha Amane

Suzuha Amane (阿万音鈴羽, Amane Suzuha), later known as Suzu Hashida, was originally a part-time employee for the landlord of Rintarō's flat and is on a search for her father in Akihabara. She enjoys riding her bicycle and appears to be at odds with Kurisu.

She is in fact a Time Traveller from 2036 who, using the guise of John Titor, seeks to prevent SERN from creating a Time Machine that will lead to dystopia. Though she is unaware of it, she is the daughter of Hashida Itaru and Amane Yuki.

Radio Kaikan
At the start of the story, in the Beta World Line, Amane safely lands her time machine on the roof of the Radio Kaikan building. What happens afterwards is not shown as, shortly afterwards, the world line switches to the Alpha World Line in which Amane's co-ordinates are slightly off and her time machine "appears" inside Radio Kaikan's upper floor, damaging itself and the building. Regardless, Amane manages to acquire a MTB bike and a phone and seeks employment at the Braun Tube Workshop owned by Yuugo Tennouji in order to get close to the Future Gadget Laboratory.

Working Warrior
Okabe first encounters her when she applies to work part-time at the Braun Tube Workshop. She appears fairly frequently but is often slacking off due to the Braun Tube Workshop's unpopularity. Okabe christens her "Working Warrior", due to her statement that she is a soldier. She forms a close relationship with Nae Tennouji but always glares menacingly at Kurisu Makise whenever she sees her. She believes Kurisu is a SERN conspirator because she is hailed as the "Mother of Time Machines" in 2036, unaware of the fact that Kurisu's co-operation with SERN was probably involuntary. As John Titor, she exchanges mail with Okabe and posts on @channel, although no-one is aware of her identity.

Search for Father
Amane attempts to meet her father at a time machine offline meet she knows he will attend. However, this meeting is prevented by an unknowing Okabe, who prevents Daru from going to the meeting. Unable to meet her father, Amane leaves after sending a mail containing the single word "Goodbye" to Okabe. She uses her time machine to leap to 1975 and obtain the IBN 5100. However, these events change after Okabe sends a D-Mail so he would pursue Amane and prevent her from leaving. Amane remains in Akihabara, although during this time the time machine is damaged by rain water. Okabe awards her the lab member no. 006 after accidentally telling her about the time machine's existence.

Last Supper    (SPOILER ALERT)
After the completion of the Time Leap Machine, Suzuha attends the celebratory dinner with the other lab members. However, she leaves after arguing with Kurisu. While she is gone, Moeka Kiryū and several Rounders attack the lab and kill Mayuri Shiina. However, Amane shows up and defeats all the Rounders. She is then trapped in a gun standoff with Moeka, giving Okabe enough time to use the time leap machine to alter history.

Fate
(SPOILER ALERT)

Amnesia
After attaining World Line Divergence 0.337187% and using the Time Leap Machine to try and prevent Mayuri's death, Okabe chooses to pursue Suzuha with both Daru and Mayuri, preventing her from leaving for 1975. Amane's identity as a time traveller, John Titor and her search for her father are revealed. Using a pin belonging to her father, the group attempt to identify him, but are unsuccessful. Meanwhile, Daru attempts to fix the flooded time machine. After fixing the time machine, Amane prepares to leave to 1975 and obtain a IBN 5100, but Mayuri interrupts and reveals to the group that she has managed to work out that Amane's father is Daru. The two have an emotional "reunion" and Amane leaves in the time machine, sending Okabe a mail containing only the word "Goodbye". However, Daru's repair was incomplete and the time machine malfunctions. Although Amane makes it to 1975, she is amnesiac and only remembers herself as "Hashida Suzu". She aids the young Yuugo Tennouji and acts as his mentor, but in 2000, her memories of 2010 return and she suffers a breakdown after realising that she failed to obtain the IBN 5100 despite meeting her father and sharing experiences with all the lab members. She writes a farewell letter to Okabe, telling him of her tragic fate, and entrusts it to Tennouji, who gives it to Okabe in 2010. After writing the letter, Suzuha hangs herself.

Suzuha's Ending
In this world line, the events of World Line Divergence 0.337187% recur endlessly due to Okabe being unable to decide between saving Amane or Mayuri, so he loops time endlessly for himself by using the time leap machine to re-live the two days Suzuha spends with the lab members endlessly. However, after possibly hundreds or thousands of loops, Suzuha realises time is looping and confronts Okabe. After discovering the truth of her suicide, she asks Okabe to come with her to 1975 to ensure that she will not hang herself and will secure an IBN 5100. Okabe's emotions begin to revive after this. The two enter the time machine and travel to the past, but what happens to them is not revealed.

1975
After Okabe prevents himself from stopping Amane from leaving after her failed meeting with Daru, she leaves in the unbroken time machine and her memories remain intact after the journey. She secures an IBN 5100 and mentors Yuugo Tennouji under the name "Hashida Suzu" (which suggests that she figured out that Daru was her father, despite not meeting him before travelling through time). However, she becomes terminally ill at the age of 54 and dies in 2000 of natural causes. Her Divergence Meter passes into Tennouji's possession. Unlike in World Line Diverence 0.337187%, she does not die in anguish and accomplishes her mission, passing on the IBN 5100 to Yukitaka Akiha.

Beta World Line
In the Beta world line, World War III breaks out. Daru invents a complete time machine that can travel backwards and forwards in time, which Suzuha uses to travel to 1975 and 2000 to secure the IBN 5100 before travelling to 2010 to save Makise Kurisu and change the past. This Suzuha is aware Daru is her father. Her personality is slightly different from Alpha world line Suzuha. She and Okabe travel back to July 28, 2010 to save Kurisu. After securing Kurisu's life and faking her death to trick the past Okabe, Suzuha disappears because, in the rebuilt future, she never time travelled back to 2010.

Robotics;Notes
After the events of Steins;Gate, in Robotics;Notes it is revealed that Daru got married and has a daughter, who may be the Steins;Gate world line's version of Suzuha. However, she doesn't appear during the events of Robotics;Notes.

Trivia

 * Suzuha's voice actress, Yukari Tamura, also voices her mother.