Sensei decides to give Chika a call in the morning so she can spend some time with him without having to keep her feelings in check. To his surprise, she’s already awake as she made waffles for Chinami and had to buy the ingredients. After a joke about their current situation, she agrees that he can visit her.
Sensei arrives at her apartment, but no one seems to be there. After a short moment of doubt on Sensei’s part, she calls out to him from the bathroom, wants him to come in and assures him that it’s safe. He enters and, as soon as he sees Chinami in the bathtub, immediately exits out of reflex as this is anything but safe in his eyes. Chika thinks that it is safe and tells him that it wouldn’t have been if Yumi was taking a bath, but he would’ve stayed in that case, which she calls him out for. Chinami asks why he left and Chika tells her that he doesn’t seem to love her anymore, which makes her sad. Chika tells him that he’s making a big deal out of it and should just come in while Chinami wants to spend more time with him as she’ll die soon and gets scolded by her sister for saying that.
Sensei wonders what he should do:
If he agrees that him being in there is normal, he enters again and has a conversation with the Chosokabe sisters which involves water bills, job hunting and Yumi. He doesn’t take their offer to wash Chinami’s hair or let Chika wash his hair as he is perfectly fine where he is. The conversation ends when Chinami mentions that Chika is worrying about something and Sensei thinks that it’s connected to their agreement. Chika begs him to wait for them in the living room and he leaves.
If he thinks that it isn’t, he makes his way to their living room and waits for them to finish.
While he’s waiting, he considers doing something to improve their lives a little, but dismisses it when he notices that it would be useless in the long run and only would make Chika more dependent of him. The sisters come in and Chika rests her head in his lap. He has an inner monologue about the formation of gaps between them, which ends with the gap between consciousness as she has fallen asleep. He notices her wet hair, which makes him wonder how long she’s been awake to take a bath herself and get ingredients for Chinami’s waffles.
Chinami appears beside her and acknowledges how fast she fell asleep in his company. She tells him that she saw Chika crying last night and notes that she hasn’t slept well for a while. She wonders if they had a fight and if that means that he won’t visit them anymore, but he has no intention to abandon them for the foreseeable future. She thinks that telling Chika that he loves her would help her through this or, alternatively, give her a little sister. Sensei tells Chinami that Chika’s daughter wouldn’t be her sister but her niece, which finally convinces her to give it a rest, though she isn’t happy. She falls asleep next to her sister and Sensei decides to let them sleep and leaves once both wake up after a few hours.