A blackmail sent to the police containing a video showing the letters "VF" in flame. "VF" means to battle with the card game "Vanguard", in other words, to "fight". The criminal's demand is to call the strongest adult vanguard fighter, and to fight him against three games.

Yu-yu is a boy living in Kanazawa, Kaga Province. He is 15 years old and in his third year of junior high school. He has the ability to sense the feeling of others, but he is troubled by the fact that he cannot say no when asked. One day, Yu-yu could no longer stand going along with his sister's hobby, so he ran away from home. The one who saves him is Megumi Okura. Megumi invites Yu-yu to a nighttime amusement park called "Wonder Hill" where her friends hang out.