Futarigurashi's plot revolves around Kenji Aoyama, an aspiring erotic manga artist, who seeks a roommate to share the rent. Unexpectedly, Hikari Satou, his friend's younger brother, disguises herself as a girl and becomes Kenji's roommate. As the series progresses, Kenji and Hikari get entangled with several women, forming the foundation of the storyline.