In this world, players participate in "Hero Battles" using Bankfon Gs, which allows them to rent powerful hero suits and fight battles against other players, receiving power boosts from the public. Kaito G?sh?, a young elementary school student who is always eager to help others, ends up hastily signing a contract to rent the powerful hero suit, Enter the Gold, from a mysterious priest named Sennen. However, he soon learns that this suit comes with a debt with 10 billion yen, which Kaito must now pay back by winning Hero Battles.