Chika returns to her apartment where Yumi and Chinami are playing a new game. Chika acts passive-aggressive towards Yumi before telling her that she's no longer welcome at her home. Yumi doesn't understand what she did to cause such a punishment, and Chinami thinks she should explain why she's mad at Yumi before punishing her, but Chika claims that throwing out a traitor doesn't warrant any further explanations. Now standing in front of her, Yumi wants to know what she did to betray her, with her only guess being her owing money to her, which Chika immediately negates, and then reveals she witnessed everything she did with Sensei on the beach, accusing her of stealing her boyfriend.
Yumi wants to talk about this on the balcony so Chinami can't hear what she has to say, which turns out to be bad idea, because once they're outside, Chika threatens to throw her off the balcony if she doesn't like what Yumi has to say. She accuses Yumi of betraying her, how this was her plan all along, and that she never cared about her, even after everything Chika did for her. Yumi, who has a hard time speaking out of fear, finally explains that nothing serious was going on between them and they only ended up physically close together due to the storm. However, Chika cites some of the sentences she said that night, and Yumi, who's on the verge of tears now, admits that she meant what she said, but she wasn't referring to what Chika thinks it meant but kissing, which is something she did with him long before they got closer.
Unfortunately, Chika doesn't buy it and feels like Yumi is just telling her a story she made up to cover her actions. After venting about Yumi hiding things from her, how even this "best-case scenario" is anything but ideal, and how she's mad at everyone, including herself for not figuring out sooner that she's been deceived this whole time, Yumi asks if she even considers talking to Sensei or if pushing her off her balcony will be enough for her to settle this, and Chika intends to talk to him next. Yumi offers to call him for her and promises to put him on speaker to ensure they don't try to deceive her, though Yumi promises she wouldn't have done that anyway, because Sensei, if he doesn't decide to lie to her, will retell that night similarly.
Meanwhile, Sensei is somewhere in the city, waiting for his day to be ruined. He doesn't have to wait long since Yumi calls him at that moment and begs him to come and talk to Chika, revealing she knows about their talk on the beach and threatens to cut her off. Once Chika takes over the call, Sensei promises to be there soon, and while Chika lets him talk to Yumi again, she ends the call without saying anything else, which he can't blame her for after he made her life harder yet again.