She loves bananas! The aho-girl, Hanabatake Yoshiko, who doesn’t care if she can’t do her studies at all, starts yet another day at school. Her carefree actions of idiocy seems to not only cause trouble for her childhood friend, A-kun, but her classmate, Sumino Sayaka, as well.

Emura Akane, Shiina Kuroko, and Hiiragi Himeko are hanging out in the classroom after school when Yoshiko sets her sights on them. The girls, completely unable to read Yoshiko's behavior, get roped into playing with her. They agree to play hide and seek in order to escape Yoshiko, but then...

In order to make the cultural festival that she looked forward to so much a success, Emura volunteers to join the cultural festival committee. Progress on the class attraction is slow, so she and her friends stay overnight at school to get some work done, but then Yoshiko enters the scene. The three girls try to get rid of her, but they get sucked into her game...