Fuyuumi Ai has forced the club to shut down. Masuzu wants Eita to get closer to her and find a weakness.

The club decides to go to the beach for their summer club activity. Chiwa asks Eita to accompany her to buy a swimsuit. Masuzu steps in to interfere with Chiwa and Eita's date, while Himeka and Ai follow Eita in secret. All of them end up spending time together. On their way home, they meet Eita's aunt, Saeko, who realizes that Masuzu and Eita's relationship is fake, and questions Eita about which girl he likes the most.