One or more heroines of this game are Youkai.

Youkai range eclectically from the malevolent to the mischievous, or occasionally bring good fortune to those who encounter them. Often they possess animal features (such as the Kappa, which is similar to a turtle, or the Tengu which has wings), other times they can appear mostly human, some look like inanimate objects and others have no discernible shape. Youkai usually have a spiritual supernatural power, with shapeshifting being one of the most common. Youkai that have the ability to shapeshift are called obake.