One day, a high school boy, Ninomiya Shungo, is ordered by Ryoko, his elder sister, to live with a beautiful girl, Tsukimura Mayu, in the same house together to cure her androphobia. As a cure for androphobia, they force Shungo to do various things like taking a bath together, or sleeping on the same bed. After Hojo Reika moves in to keep an eye on this "training" between Mayu and Shungo, the house has become quite lively.