Due to certain circumstances, Tetsuo’s younger sister Yuri was accepted into Saint Ouka Academy, a girls’ school for the upper class. Since she was quite shy and only a member of the lower-middle class, she thought it would be impossible for her and looked to her big brother for help. It ended up with him dressing up as a girl and attending school with her. However, he wasn’t a pretty boy or a natural trap, but just a manly man. With his broad shoulders and muscular frame, he was constantly watched by dubious eyes and Yuri did her best to help keep his secret.
One day, a fellow dormmate Shizuka invited him to join the drama club since they were lacking people to play male roles and he would be a good fit with his manly frame. After Tetsuo and Yuri joined, they discovered the club’s secret: it is actually a place for those girls who are deathly afraid of males to overcome their fear via practice.