Shiratori Ryuji wants to become a picture book writer, and he moves to an apartment, Narutaki-So, in order to go to an art school in Tokyo. The Narutaki-so is an old Japanese style one-story house which doesn’t fit in with the urban scenery. It's owned by the cousin of his mother, but the manager of the apartment is Aoba Kozue. She is his second cousin, and they met with each other when they were children although he doesn’t remember her much. She is in the second year of a high school attached to Aoba Junior College.

There are five people living in Narutaki-So. First, Chanohata Tamami is living in the room #1. She is a best friend of Kozue. Then, the resident of the room #3 is Momono Megumi. She is a kind of person who goes her own way. In the room #5, Kurosaki Sayoko and her daughter Asami are living. Asami is in the first year of a junior high. Finally, in the room #6, Haibara Yukio is living with his puppet, "Johnny".

They are all characteristic and eccentric people. However, in fact, the most eccentric person is Kozue. She has a secret; when she is shocked at something, she changes her personality. Not knowing this, Shiratori moves to Narutaki-So to realize his dream. What kind of a new life will be waiting for him?