Dojuku Academy in Sapporo City, Hokkaido, is a private elevator school for boys, and famous for its strong academics. It was founded by the wealthy businessman Kaneshichi Fujita. Based on his policy, the burden of paying tuition from the moment the school was established has been free of charge to the students of the school and their families. Takashi Zaizen is a new student entering the school with full marks. Hoping to join the baseball team at the beginning of the school year, he meets an older student who offers to show him the way to the baseball club room. However, he is instead led to a room past a door in the back of the library, located further underground. A few students playing mahjong introduce themselves as the Investment Club, a club that makes the money needed to operate the school. Zaizen invests in a variety of sectors such as stocks and ventures, meets the grandchild of Dojuku’s founding father, Miyuki Fujita, and learns that his own great-grandfather was the founder of the Investment Club.