Hyakki Yagyou (百鬼夜行) is the first mini-album by Kaya, released on July 11, 2007.
Hyakki Yagyou contains five tracks, all of which share the theme of「夜」(night). The title is derived from the Japanese folk belief of demons parading the streets during summer evenings. It literally means "The Parade of a Hundred Demons", and Kaya himself drew the parallel to mythology by naming three of the songs after Japanese demons. "Kugutsu", or puppets, are also familiar in Japanese ghost stories.