The time is Edo.

Ichitarou, the young master of Nagasakiya, one of the largest stores in Nihonbashi, has been in poor health since birth and is unable to go outside. Ichitarou is always protected by spirits such as Shirasawa and Inugami, who serve him.

One night, Ichitarou sneaks out when no one is looking and witnesses a murder. From that day on, bizarre murders begin to occur one after another in Edo... With the help of the spirits, the search for Ichitarou's culprit begins!

(Source: Official website, translated)