The two finally make it back to the lab, where Kurisu and Ruka have begun cooking. Okabe doesn't believe it, even though Suzuha says that he is the very person who conceived the theory, and that even with the slim chances it's worth the risk.

Rintarou's first plan in changing the past is… winning the lottery.
This causes Faris to notice, and she asks who with (even suggesting it's Kurisu), before saying that "all this women chasing" will tamper with his "special technique".

Kurisu has also tried to research about the IBN 5100, and discovers that, like Rintarou explained earlier, the IBN 5100 can in fact analyze special programming languages. Mature as she is, Kurisu is very sarcastic, and often expresses this through her interactions with Okabe and Daru, the former due to his eccentricities and frequent insensitivity and the latter due to his perverted remarks. However, he ends up running into Past Kurisu, and nearly suffers from a mental breakdown.

She notes that she will need many parts, which Okabe proceeds to buy. After Mr. Braun's suicide and at Kurisu's persuasion, Okabe prepares a D-mail from Mr. Braun's phone telling Moeka to stop pursuing the IBN 5100 at all, and sends it.
Kurisu Makise is the deuteragonist and lead heroine of the visual novel and anime series Steins;Gate, as well as one of the main protagonists of the sequel Steins;Gate 0. Rintarou then asks about the current whereabouts of the IBN 5100. Okabe, getting the knife, tries to stab Nakabachi, but at that moment Kurisu manages to push Nakabachi aside, and in the process, Okabe stabs Kurisu, revealing himself as the true murderer.

Okabe promptly says that that wasn't his first kiss, but that the first one wasn't romantic (implying that time he had to kiss Moeka, although Kyoka no Dejà Vu changed that). Once more in the lab room with Kurisu and Daru, Okabe, frustrated and fed-up, goes to break the Time Leap Machine, but Kurisu stops him, saying they had already decided not to use it. The part of her name "Kuri" means chestnut, and so her hair color is most likely to resemble the color of a chestnut. When Okabe asks about Mayuri's welfare, Moeka says she is “unnecessary” and shoots Mayuri in the head. At Staples Center the next day, Faris manages to score big at the Rai-Net tournament while Daru cheers her on, and Mayuri manages to get Ruka in female cosplay again, to his embarrassment. Kurisu mocks this since evil geniuses don't typically accept such things, but this causes Okabe to breakdown, saying that he's no evil genius and that Hououin Kyoma is a piece of child's play. Okabe walks into the building when he notices Past Okabe heading for the roof, having heard the time machine. He then asks Kurisu what her opinion is, at least that very moment. He and Kurisu send the D-mail that will undo it, but it doesn't work again. Kurisu is a research member in Victor Qondria University's Brain Research Program. Her hair color differs considerably in the anime (red) from the original VN (chestnut).

Not getting the question, Okabe declares himself a mad scientist, but this causes the police to deem him mental and promptly handcuff him and take him away. Upon inspection, though, he quickly finds that he is wrong and that Ruka is, in fact, a girl. More than liking the pool itself, she likes the feeling of floating in water. After a few awkward moments of silence, Okabe glances at Kurisu and starts to head for the car, when Kurisu asks him to come inside to discuss something. Just as Okabe is about to concede, Kurisu also mentions that the IBN has to be in the coin locker for a reason: so that FB can come and pick it up, meaning that if Okabe sits outside the locker room and waits, he can see FB. Okabe decides to elaborate by saying that, while the alternate world lines are real for him and she was always his constant, he just wants to know what she feels in the current world line. Kurisu is generally a sensible, serious mature young woman, usually calm and collected even when someone is acting tense in front of her. Instead, Kurisu asks about the other world lines, as like with Mayuri, she is starting to experience memory dreams, apparently having not awakened all of the memories. Kurisu Makise (牧瀬 紅莉栖, Makise Kurisu?) He then begins walking down the street in front of the now-intact science building, and has he does, he manages to pass by Kurisu, who has been spending her entire time looking for Okabe in order to thank him for saving her life. Kurisu is then seen watching their plane, and when the group gets to check in, the passport official asks for reason of visit. However, as he gets the lightsaber ready, he discovers to his horror that the fluid has dried up just as Nakabachi appears.

Okabe then has Kurisu go back to the lab to get the phone wave, but Mayuri starts complaining that Suzuha never got to meet her dad. That night, Kurisu comes to Radio Kaikan building where Suzuha's time machine had crashed, and within the darkness she found the room where she was stabbed in another worldline. His clothes are covered in Kurisu's blood.