Board Thread:General Discussion/@comment-6192846-20140918010005/@comment-9410476-20150107101223

I had a theory along with Ninja that the song is based on the story of momotaro. A man goes to a rumored "demon island" and finds four demons and they reveal their story of being murderd and having exacted their revenge on their murderer, a tailoress, this turned them into "onis". I'm guess they haunt the entire island in their rage and the visitor has to put a stop to them.