Kinoshita Mairu possesses a cute name, for which she feels apologetic because she is ugly. Indeed, she apologizes for her very existence since she is not cute. Classmates refer to her as "Poison Mushroom" behind her back, and even her own brother treats her with disdain. However, all of that is set to change with the assistance of her transvestite mentor and neighbor, Fuwari-chan, and the "school king," Kumada Tenyuu!