Age: 18 (Steins;Gate), 19 (Steins;Gate 0)
Birthdate: December 14, 1991 (Sagittarius)
Blood Type: A
Height: 177 cm (5'10")
Affiliations: Future Gadget Lab
Occupation: University Student
Rintaro Okabe (岡部 倫太郎 Okabe Rintarō?), often nicknamed Okarin (オカリン) or Hououin Kyouma (鳳凰院凶真), is a self-proclaimed mad scientist and the main protagonist of the Steins;Gate series.
Okabe is a theatrical and eccentric individual. He is a self-proclaimed mad scientist, who likes to assume his "true name" "Kyouma Hououin" (鳳凰院凶真, Hououin Kyouma), and often uses this to introduce himself to others. Usually, people do not care and instead address him by his actual name or by 'Okarin' (his nickname), much to his chagrin.
Okabe is also socially inept; his social skills were so poor that Kurisu considers the childlike Mayuri to be usual by comparison. However, he isn't hesitant to lend a helping hand to people whom he'd never met. Although very intelligent, Okabe is easily deceived by others.
Okabe likes to pose as an agent working against a specific "Organization," which he suggests is always after him, as he believes this kind of image gives him an excellent and mysterious aura. However, this seems to disappear as the story progresses, with SERN likely replacing the "Organization's" villainous image. 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.
It is later revealed that his 'mad scientist persona is essentially a façade to make life interesting for his dear childhood friend Mayuri. After her grandmother's death, Mayuri fell into deep despair, but Okabe snapped her out of it by acting like an anime character and declaring her his hostage. He later drops his Chuunibyou façade upon witnessing Mayuri's multiple deaths, revealing a serious side of himself he has not shown for the first half of the series.
As a result of going through dozens of time-leaps, he becomes somewhat 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.
After Kurisu's death in Steins;Gate 0, he becomes ever the more miserable, to the point of experiencing panic attacks from remote references to Makise Kurisu and having to consume anxiety medications actively. He had also abandoned the identity of Hououin Kyouma in its entirety, choosing to live as an ordinary university student to significant discomfort within his circle of friends.
He and Itaru are both students of Tokyo Denki University and have been friends for roughly three years. However, Itaru claims that their friendship is only just over a year old. He is an engineering student.
Rintaro founded the "Future Gadget Laboratory," a small research institution situated above a CRT store. It is an area where he and his fellow Lab Members create "Future Gadgets for the betterment of mankind." He dubs himself Lab Member 001 (the first to join the lab).
Rintaro has an enduring relationship with Shiina Mayuri - Lab Member 002 and co-founder of the "Future Gadget Lab," whom he made a vow to protect when they were young.
He lives an average life with his small group of friends until he creates the Phone Microwave with Itaru. His parents run a family business, and he has once gotten an eggplant for Christmas.
At the beginning of the show, Okabe attended a seminar about the fundamental theory behind creating a time machine. Shortly after the symposium began, he got expelled from the seminar because of accusing the professor of plagiarizing the idea from John Titor.
Afterward, he heard a scream from upstairs, rushes to the source of the sound, and eventually finds the dead body of Kurisu Makise in a pool of blood. Shaken by the incident, he immediately contacts his friend Itaru about it. Right 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.
Five days later, while attending a lecture that afternoon, he meets a perfectly unharmed Kurisu Makise. Although he was confident that the events happened, he double-checks the occurrences on the Internet, coming up with the confirmation of what Itaru has told him.
Shortly after agreeing to let Kurisu join his lab, Okabe soon realizes that the Phone Microwave is a time machine. With the help of Kurisu, Okabe starts doing experiments with the Phone Microwave by sending emails.
Okabe starts doing experiments with the Phone Microwave by trying to send text messages to the past. He finds out the experiments only work at a specific time of the day; if the D-mails can affect the past, then D-mails will alter the present. Only Okabe can notice the change, as other members' memories have also been changed to fit the new timeline.
Later on, he learns that he possesses a special ability to retain memories between the world line changes. He names this ability Reading Steiner.
After sending several D-mails, Okabe has changed the world line drastically. Besides losing the IBN 5100, he received several threat mails from an unknown person.
Soon a group lead by Moeka raids 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. Okabe then begins to be terrified of Mayuri's death every time he sees Mayuri's watch stops.
By confronting Suzuha after time leaping, Rintaro now learns that Suzuha is, in fact, John Titor. Rintaro also finds out more about the world line and Attractor Field. In the future of this Alpha world line, Rintaro becomes a terrorist leader. Kurisu is the mother of the time machine that enables SERN to complete world domination and that he cannot save Mayuri due to world line 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.
After undoing Moeka's D-mail, Rintaro notices that he'll end up in a world where he cracked SERN's Database and deleted the first D-mail by using the IBN 5100 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, and they kiss each other. Rintaro finally decides to sacrifice Kurisu and return to the original Attractor Field.
Now, in the original world line, he receives a phone call from Suzuha. When Rintaro meets Suzuha, she tells him 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.
After returning to their time, Rintaro was devastated for killing Makise Kurisu. Nonetheless, he awakens from his delusions and receives a message from himself in the future.
The message tells him that the way to save Kurisu without altering the events is to fool his past self into believing Kurisu had been killed. The second thing was Mayuri's Metal Upa not to be detected by the Metal detector in the airport, and let the files that were 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.'
Quick reminder:Towards the end of Steins;Gate 0, Okabe stepped into the time machine to achieve the perfect world line: Steins; Gate. However, the time machine malfunctioned right after the launch. Instead of traveling to the past, Okabe's mind ended up transferring to the future alpha world line.
In the future of the Alpha world line, Okabe became the leader of the resistance against SERN's rule and was known as an international terrorist. It is later revealed that SERN released Okabe and Daru to find the resistance, thus completing the cycle of fate. However, Okabe got captured by SERN's Rounder unit in 2025 and was tortured. When Okabe later was found, the endless torturing and experimenting had done so much damage that his mind was as sound as dead.
After waking up in the future alpha world line, he commenced ''Operation Skuld'' with future Daru, Maho, and the other lab members.
To start the ''Operation Skuld'', Rintaro returns to the past. He obtains the Metal Upa first before his past self does. Mayuri will then 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 blood to recreate the scene where he saw Kurisu lying unconscious on a pool of blood to save her.
In the end, he walks through a crowd of Akihabara when someone familiar passes by him. He stops and turns around, not believing what he'd seen. The person turns out to be Kurisu. She smiled thankfully and remarked that she was afraid of never seeing him again and would forever be unable to thank him for saving her life. Okabe tells on 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 the tongue, he calls Kurisu by the nickname he used in other world lines, 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 realizes 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. Rintaro continued living in this Steins;Gate worldwide happily, with Kurisu and Mayuri safe and sound.
After going through a grueling journey across multiple World Lines, Okabe has assumedly landed in the "Steins Gate" World Line. In this world line, both Makise and Mayuri were living, and SERN was not ruling the world because there was no such a thing as a ''Time Machine''.
Eventually, Okabe starts having intense side effects from his time travels, seeing visions of alternate Worldlines. In the sequel, Suzuha Amane revealed all the memories of the world line Okabe has visited, causing him to fluctuate between two world lines.
To save Okabe, Kurisu returns to the past, succeeding in her mission by implanting the concept of Kyouma Hououin into Rintaro's mind and giving him his first kiss, which led him to take on his ''Mad Scientist'' persona to protect Mayuri. With this, Kurisu manages to bring Rintaro back to the Steins Gate world line.