After her parents were killed by monsters, seven-year-old Yayoi Shirakawa was adopted by her relatives. Unexpectedly, her relatives had two little devils. They were known as the most genius and most disgusting slayers of the Shirakawa family.
When she was ten years old, Yayoi summoned Yamata no Orochi from hell. In the chaos, Yayoi escaped from the Shirakawa family with Yamata.
I never expected that many years later, the three of them would meet again in a funny way...