The anime centers around Kaito, an elementary school boy who is suddenly burdened with 10 billion yen (about US$100 million) in debt one day. The only way he can pay off the debt is to master "Hero-Gi" (downloaded off the net) and win matches in "Hero Battle," a new-generation cyber sport. The tagline of the game "Change your money with justice!"

(Source: Anime News Network)