Ichiba Kurogane is tired of living off his parents' wealth and decides to attend Gakuenzono Institute, a school on an island where 300 thousand students are graded by the amount of money they can earn.

Misfortune strikes him as his wallet has been taken into custody and being confronted by Student Council President Amatsuri Hagane. Due to having an unlimited credit card with him, he was charged by the maximum amount possible: 100 million Gakuen.
Will he be able to manage the greatest debt on the island?