A new love letter every day is placed in Eita's shoebox, but before he can deal with it a new girl shows up and kisses him in front of Masuzu.

Eita read Ai's delusions note by accident. As apologies, Eita accompany Ai to the local festival. Ai reveals herself to be Eita's childhood friend in kindergarten. However, much to Eita's surprise, they are also engaged to each other as their childhood promise. The club is reopen with Ai joining the club as club adviser.

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.