The setting is Edo. Ichitaro, the young master of Nagasaki-ya, one of the largest shops in Nihonbashi, has been frail since birth and can rarely leave the house. Around such an Ichitaro, yokai like Hakuzaku and Inugami serve and constantly protect him. One night, sneaking out away from prying eyes, Ichitaro witnesses a murder. Beginning that day, a series of bizarre murders start occurring throughout Edo... With the help of the yokai, Ichitaro's search for the culprit begins—!