Going to the research lab, Kotonoha met a friend, who thought there are probably lots of girls in her lab, as on her place it's mostly men. Kotonoha thought it was rare, but indeed they were 3 girls there. Kotonoha continued to the information science department, where she statistically analyse information all from the world. The lectures in the information department end in the 3rd year and the 4th year students are assigned to their own sections, and in the research room, they conduct research and write dissertations. But upon entering the research room, no one was researching and Ena was sleeping on the couch, likely from playing again all-night video games. That was possible, since the research room is a public space, where anyone can come and go, bring stuff or eat their meals. Kotonoha then saw Ayame and Shinya, who were still working on their love experiment. Seeing the puzzled face of Shinya, she asked him if there was trouble and he explained that they did the "kabe-don" experiment about 200 times and as time went, her heart rate was decreasing. Kotonoha quickly understood that Ayama just got used to it. Ayame also mentioned that at first her heart rate was racing, but later she was casually wondering what was Shinya doing. Ayame then brought up something she noticed and showcased a picture of Shinya doing the "kabe-don" and they both realized it looked like the sumo move "kabe-harite" and doing it that fast naturally won't get the girl excited, so they need to fix the timing of doing the kabe-don. A bit shocked, Kotonoha left them.
Kotonoha then went to her desk, where Ayame also came and asked her if she decided the them of her research. As Kotonoha was still reading essays and deciding her research, they considered something like "optimization problem" and puzzles seems fun. Ayame then gave example of optimization problem with a possible puzzle in it, like the mailman finding the shorted road to deliver mail to randomly placed houses. Kotonoha got a bit excited as she loved those type of mathematical puzzles and remembered how fun she had when her mathematical teacher in high school was often giving them such puzzles. She specifically remembered a situation with her teacher, where she solved the tower of hanoi puzzle and the time she had with the teacher explaining it to her. Kotonoha then mentioned she really liked that teacher and was wanting him to look at her, so she studied hard and because of that she took science as major. Then Shinya using that conversation wrote a hypothesis on Kotonoha's love. He asked her how many other people she fancied in the past and that there may be a common area with Kotonoha's love and Ayame's love. Kotonoha was embarrassed he kept speaking of her love and wanted him to stop, but Shinya wanted she to detail all of her other loves too, to seek a common area. Ayame then stepped in and smacked Shinya on the head, telling him that normal people are embarrassed to talk about such things and because of that he doesn't have friends. But Shinya told her he only wanted to make clear Ayame's feeling of love and that he didn't care if others hate him and using that moment, Kotonoha managed to leave.