Xiao and aether were best friends from childhood, although they hid it from the world. Aether was an angel's prince and xiao was a demon's prince. Their fathers were worst enemies. But now Aether and his father were invited to hell to discuss something... "I propose to live in peace and stop the war. To bond our kingdoms xiao and aether will get married." xiao's father says with formal voice. Aether's father instantly agrees leaving no choice to the boys.