Where did she come from? Just who is she? The female hive Toda mowed down a swarm of powerful cyborgs.

It is the Early Showa Period in the Imperial Capital of Tokyo. Times are hard but there is talk that times were much worse until a certain "evil" was vanquished. Now Tokyo is in the grips of lesser evils and mysterious rumors... Especially those pertaining to the "Byakko" and the "Monster of the Juunikai" ... Just what are they? Are they something to be feared? To be admired? Or more? And when the "evil" returns... Just whose side will they be on?

Fushimi and Toume were just a normal boy and girl going to high school until one day they stumble upon a phantasmal mountain known as "Mount Hagure" .
Before either of them knew it, Toume was possessed by a yōkai named Dakini, a goddess that grants wishes.
When Fushimi is asked what he wishes for, his response is: Give Toume back. Dakini says she can grant the wish but in return he must become her servant. The deal is struck. Fushimi has now become Dakini's servant and Toume has been returned. Darkness, however, is afoot and now Fushimi must take on a more active role as Dakini's servant. Is he up for the task?