Mizuki has finally gotten away from her nagging parents and is going to boarding school, like she always wanted. However, due to an administrative mix-up, she ends up being sent to the boys' dormitory instead of the girls'. There, Mizuki meets her roommate, Ichinose, who pounces on her almost as soon as she arrives. It seems that Ichinose can't help turning into a beast when he's in the dark! Even though he's normally an absolute sweetheart, he transforms at the flick of a switch. Ichinose makes Mizuki feel incredible, but his sudden change is still quite startling!