Shungo is a normal high school student living in a huge house. One day, his sister Ryoko sends Mayu and Mikihiro Tsukimura, two siblings, to live with him to help Mayu overcome androphobia (fear of men). Unfortunately this is acomplished by making Mayu and Shungo share the same room, bed, and even baths together. Making things even worse, Reika Hojo, the student-council chair, ends up becoming their maid due to a video shot of her which Ryoko takes while Reika tries to seduce Shugo as a blackmail.