Four high-school boys are playing hooky on a class trip when they accidentally discover an alien eating the body of a female classmate. Not quite knowing what to do about it, they are afraid they might be the next victims of this mysterious entity if they tell anyone about it. However, when the boys slowly start to disappear, the remaining friends end up paying a strange doctor several thousand yen to protect themselves.
With the doctor's help, they discover that the cannibal was actually an alien living on Earth who was among the last of its kind after a brutal civil war destroyed their home planet. Normally, members of his race ate the women when they mated with them. However, this kind of alien evolved and started developing emotions and feelings of love for the girl. Unfortunately, he couldn't stop the compulsion to eat her and cried out as a result when he finally gave in.
Later, it turns out that this story is just a pitch that the Prince is giving to a publisher in order to expand the humans' awareness of aliens living on their planet.