On her sixteenth birthday, orphan Himari Momochi inherits her ancestral estate that she's never seen. Momochi House exists on the barrier between the human and spiritual realms, and Himari is meant to act as guardian between the two worlds. But on the day she moves in, she finds three handsome squatters already living in the house, and one seems to have already taken over her role!

Himari Momochi inherits Momochi House, an estate that exists on the barrier between the human and spiritual realms. Four friends come over to visit Himari, but Aoi can sense that one of them is no longer alive. This spirit is absorbing Momochi House's power and is quickly transforming into a demon. Will Himari be able to stop its progression and save her friends?