An apartment standing in the Tokyo suburbs. There a family of four — Chikara Nakagoshi (Jun Matsumoto), his wife Akari (Aya Ueto), their daughter Airi (Erena Kamata) and son Kotaro (Yosuke Oohira) moves in. An indecisive husband unable to ignore people in trouble, his efficient, reliable wife, their slightly mature daughter and childish son. Their new home is full of unique residents.

Chikara immediately encounters Yoriko Michiko (Nanako Matsushima), his horoscope loving next-door neighbor. Below lives Maria (Sonin) whose is visited by many men, plus their slightly suspicious landlord (Kazuyuki Asano) informs them that Room 601 houses Boy A, the serial child killer. Chikara is interested, but Akari admonishes him, telling him not to stick his nose into his neighbor’s business…

A few days after they move in, they hear a scream from next door!
The person living there should be Manabu Kitsugi (Yukiyoshi Ozawa), an elite businessman and his happy family with wife and child…
Chikara ends up peeping into the forbidden secret of the Kitsugi family…!?