Natsuo is upset about Hina's relationship with her boyfriend, and is encouraged by his best friend Fumiya. He asks Hina to break up with her boyfriend, but ends up kissing her. Hina slaps his face, then returns the kiss and pushes him onto her bed. After seeing the shock in his eyes, she tells him that he is still a child and should not interfere in her life. The next day, Natsuo leaves the house to stay with Fumiya, upsetting the household. Rui meets him at Fumiya's house and, after discussing how to break up Hina's relationship, they return home.