Yamada, a student preparing for his entrance exams, looks forward to passing Hotaru, the busty beauty who lives next door, at the local convenience store or on the way home. One day, he witnesses Hotaru getting changed through a gap in the neighbor's window! And after she gets changed, she's not wearing a bra! That's right, Hotaru is not wearing a bra on her days off. And Hotaru has come to Yamada's house without a bra, wanting to share some with him. The timid Yamada is just upset, but his friend Odagiri, who happens to be in the room, hugs the defenseless Hotaru...