Hikaru is unreliable, can't talk with girls. Makoto, his older sister, can't stand it, and plans to train him severely. Meanwhile, he peeks into the dressing room for girls with his friends, but they are detected. Of course, Hikaru is forced to do it. Makoto's training program starts to punish him. But Mari, their relative, tries to train Hikaru in her own way. Will Hikaru be trained properly...?