Shion, a succubus who can no longer handle the oppression he faces in the demon world.
To free himself of such a life, he flees to the human world with a plan to marry a rich and powerful man.

Eldest son of a successful family, Shuusaku Saionji.
After his proposal and forcibly moving in with him, Shion gets to know Shuusaku while "feeding" on him once a week.

Shuusaku has his own troubles as a result of being part of such a prestigious lineage but finds himself fascinated by Shion's nature...

From nothing but fulfilling a hunger (for semen) to a passionate love story!