Mao Hoshimi is a typical junior high student, albeit a small and somewhat feminine one. However, during a bath with his best friend Shunsuke Hidaka, Mao undergoes a startling transformation - he turns into a girl! But this is only the beginning of his shocking discoveries; Mao soon learns that he is actually an alien. Due to the scarcity of his species, they have evolved the ability to change their form to mate with other species, as well as switch between male and female forms to accommodate potential partners. Now in the throes of puberty, Mao is destined to become a desirable mate for anyone he comes into close contact with - whether it be the cute new girl Tomoko Yokawa, or even his best friend Shunsuke, much to his dismay.
