"Something must be wrong for you to use my actual name."-Kurisu to Okabe

"I am a scientist, I have to act on my own theory. I can't let my emotions get in the way. But it's impossible to forget everything... because I've known you for longer than we've lived. This is reality. This is the world. This is..."

"People's feelings are memories that transcend time."

"Say it right, Hououin Pervert-Kyouma!" -Kurisu to Okabe.

"I've only lived 18 years, but I don't want to change any of them. They're all part of my life, even the failures."

(To Okabe, at Mayuri's grave) "You've pretty much figured it all out by now, right? That there is no absolute justice in this world. The opposite of justice is... another justice. Choosing the past through Time Leaps is just choosing between these justices. Can you say that your justice is correct?"

Rintaro Okabe (岡部 倫太郎 Okabe Rintarō?), often nicknamed Okarin, a portmanteau of the Oka- from his surname and the Rin- from his given name, is a self-proclaimed mad scientist and the main protagonist of Steins;Gate.

Okabe is a melodramatic, eccentric and rarely tsundere individual. He is a self-proclaimed mad scientist, who likes to assume the nickname "Kyouma Hououin" (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, due to the fact that there is essentially no-one he calls by their real names, and he in particular calls Kurisu a number of names that irritate her to varying degrees.

Okabe is 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. Before that, he examined her body after discovering with shock that she was alive, which caused Kurisu to believe she was being groped by him practically the moment they met (in that timeline). His social skills are so poor, in fact, that Kurisu considers the childlike Mayuri to be normal by comparison. 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 realising 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 thinks 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. He usually gives off the impression of being delusional and paranoid, engaging in strange mannerisms such as talking to himself on the phone and engaging in fits of maniacal laughter often; he seemed to have a severe case of Chuunibyou at the start of the series, but it is possible to realize that he is not delusional. There are several occasions, since the first episode, that the anime displays what goes on in his mind. In those moments the character reveals, by his thoughts, that he is very rational and concerned with the situations occurring around him and his friends.

It is later revealed that his 'mad scientist' persona is largely a facade he wears in order 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 a cartoon character and declaring her his hostage. He later drops his Chuunibyou facade 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, while 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 also 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 thing was her fault for not going straight back to 1975 and instead stopping in 2010 to find her father.

He and Itaru are both students of Tokyo Denki University, and have been friends for roughly three years, according to his words, although Itaru claims that their friendship was only about a year old.
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 always been close friends with Lab Member 002 and co-founder of the "Future Gadget Lab", his childhood friend Mayuri, who he made a vow to protect when they were young.

Rintaro lives an average life with his small group of friends until he creates the Phone Microwave with Itaru.

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 it's owner since Kurisu in this worldline has no memories of the 3 weeks she spent with Rintaro in the Alpha worldline.

In a slip of tongue, he calls Kurisu by the nickname he used in other worldline, Christina. Kurisu replies 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 worldline. But then he come 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.

Kurisu Makise (牧瀬 紅莉栖 Makise Kurisu?) is a genius girl who graduated from university at the age of seventeen. Her research on the brain's memory retention system has earned critical acclaim in the scientific community. She later joins the Future Gadget Lab as Member 004 after a series of encounters with Rintaro Okabe.

Kurisu says that she is not good at sports, but she loves swimming. More than liking the pool itself, she likes the feeling of floating in water. Kurisu describes it like you have been released from gravity, like a load has been taken off your muscles. Swimming puts Kurisu in a good mood, to the point that when Okabe calls her "Assistant", she does not retort towards the name. Kurisu can swim very well, despite Okabe's beliefs in that everyone was a "hikikomori".

Her accomplishments in spite of her youth have exposed Kurisu to the jealousy of those who consider themselves her betters. This includes her own father, who despises her for overshadowing him and causing his fall into obscurity. This is the reason behind her acerbic attitude, which she adopted as a defence mechanism to hide her vulnerabilities. At heart, Kurisu is a very curious girl who loves science and can not resist an interesting experiment. She occasionally makes statements - for example, that data collection should be considered before a subject's privacy - that have led Okabe to dub her a fellow mad scientist, much to her annoyance.

July 28th, Makise Kurisu first meets Rintaro Okabe at the Akihabara Radio Hall, claiming to have bumped into him 15 minutes earlier. She is later found by Rintaro lying in a pool of blood, and Rintaro texts Itaru about it.

After everyone's memories apparently disappear, Rintaro meets her, apparently in perfect health, at a lecture. He touches her hair, pulled her jacket in an attempt to verify that she is actually alive, and they argued until Kurisu has to begin the lecture. At the beginning of the seminar, she claims that time machines are impossible, resulting in Rintaro challenging her claim, and she turns the lecture into a discussion.

Kurisu, while being a proper Japanese name, is also the Japanese pronunciation of the western name Chris. This is likely the origin of her nickname Christina.

Okabe gives Kurisu several nicknames over the course of Steins;Gate, only calling her by her real name in serious situations. Kurisu's most frequent nicknames are "Assistant" or "Christina" (by adding '-tina' to 'Kurisu'), but Okabe also calls her "The Zombie", "Money Bags", "@Channeler", "Mongolian Spot", "Experiment Loving Girl", "Perverted Genius Girl", "Cold-Blooded Perverted Girl Genius", "Experiment Loving Perverted Genius Girl", "Celeb Seventeen" (sometimes shortened to "Celeb Sev"), "Celeb Thirty". Even though Kurisu seems to hate being nicknamed, she thinks it is hopeless to point that out to Okabe.

Kurisu is known by lab members and Okabe especially as the source of evil, even worse, the terror in the kitchen, as they despise Kurisu's many-a-times questionable cooking skills and taste palate. Okabe once stated that the lab will fall into the pits of Hell if Kurisu ever cooks, even when Mayuri is helping her and Luka once complained that Kurisu's apple pie tasted like death. She even tasted Okabe's gel-nana without any hesitation, even when Okarin and Daru warned her.

Regarding the 'What I wanted the most now is my fork', it was supposed to be a birthday gift from her dad, Shouichi Makise back when she was 7 years old. However the gift was not delivered due to an argument between the two and was kept in hold by Shouichi's good friend, Akiha Yukitaka.The gift will then be delivered to Kurisu before she time leaped to convince Okabe to not give up on Mayuri and seek help from her (the first time she tells Okabe that she knows that he time leaped). This can be found in Kurisu's Story in Steins;Gate Linear Bounded Phenogram (Visual Novel).

According to Okabe, Kurisu's lips are warm and possess a faint smell of lemon

Though hesitant to confess her feelings for Okabe, she does, in fact, loves him. This has been shown many times through out the series and most noticably when she was drunk.
Her emotions can change rapidly whenever Okabe's around