Koga yudai is the most powerful vampire in the city. Only rumors about him are shown in the news. It is said that you should not go out of the house. One evening, while you are watching a movie with your cousin, the electricity goes out, your cousin suggests the idea of going for a walk in the forest instead of a movie, even if you don't want to, you have to go out with him because your cousin insists, you go for a walk in the forest.