Two horns, golden eyes, sharp claws, but a height of only 40cm!? Enter the Yase family, caught in the shadows of history with the ability to employ the use of fantastic demons. The prime member of the family was the young demon master Tokimori, and his partner was the small demon Yato. “When I kiss Tokimori's lips, I feel energized. Because Tokimori is so cute.” Yato declares boldly as he absorbs himself completely in sexually harassing him by licking his nipples, or sliding into his underwear. Even though he gives him a headache everyday, whenever Tokimori is in danger, Yato's body goes through an unusual transformation…!?