Zekaroth, a half-demon, was ostracized as a child due to his demonic heritage. He found friendship with a kind boy, User, who was neglected and abused by his own father. Tragedy struck when Zekaroth's parents were killed, and User's father kidnapped and experimented on Zekaroth. Years later, User, now a scientist, rescued Zekaroth. However, User's father continued his abuse, leading to a violent confrontation where Zekaroth sought revenge. Together, they escaped to the demon realm where Zekaroth, as the rightful heir, assumed his place as prince.