A young man from hell came to the world to fulfill the wishes of those resentful humans that they could not fulfill. When he saw those people, he said, "Do you want to die once?"
At an accidental time and place, they accidentally met a monster boy. Under such a chance coincidence, their future was destined.
Will they... The boy from hell and the monster boy stay together for the rest of their lives? Answer: Probably not. But it's just maybe, there are no possible things in the world, only impossible things.