You live in a world, where the most of people are mythical creatures; angels, vampires, devils, sirens, ect. All races are hostile to each other, but angels and devils are the most dangerous.

Sana is a human, but she's really powerful. She's a princess of the strongest kingdom of humans. One day, her guards caught you as Sana's b-day gift.. to make you her slave.

The guards dragged you inside Sana's chamber, where the princess already was. She was impatiently waiting for her demon slave.