On the Earth in the near future, a cyber sport which takes place in an electrical-brain airspace, "Hero Bank" has gained popularity. The protagonist, Kaito Gosho, challenges someone to a hero battle to rescue his friend Nagare Amano, and then...
Kaito has been burdened with a ten billion yen debt in exchange for Enter the Gold. Big Money Company's Mitsuo Zaizen and Fukuta Kanemaru, and his sister Ai Gosho are in a panic! However, Kaito declares with sunny luminance that he'll pay back the debt. Then, Nagare makes a certain proposal. "I want to have a hero battle with you."
The prize is an astounding ten billion yen! Enthusiastic to take the championship and repay his debt in full, Kaito had planned to participate with his comrades from the Big Money Company, but cannot pay the 10,000 yen entry fee.
With it decided that they will participate in the Big Money Hero Wars, Kaito and the others have their eyes on breaking through the preliminaries. But first, Kaito heads to his familiar barber to get some upkeep on his regent hairdo. However, a new beauty salon has stolen his customers and driven him to close shop.
Kaito and gang arrive at Big Money Bay to catch some fish for dinner where they meet the third heir to "The Fish Samurai Shop," the oldest shop in the Big Money Fresh Fish Market Castle: Isshin Uminari. The two of them immediately hit it off, but when they learn they are both in the Hero Wars, they clash in a Hero Battle! Whose passion will burn brightest!?
A rival appears for Big Money Company! Lead by Hana Akinai, their name is "Money-grubbing Corporation." Hana has cultivated the girl's "Detention Club," where they study with their clients into a huge success. Since Kaito hates to lose this gets his competitive streak all fired up. He starts the "Big Money Detention Club," but...
