Set in Tenma, Osaka. Matsukichi (Kento Hayashi) is the son of a samurai. His father is killed because of a grudge and Matsukichi is also in danger. At this time, Wasuke (Masahiko Tsugawa), the owner of the store Ikawa, saves Matsukichi's life. He then begins working at the store.

Matsukichi soon considers giving up the idea to become a samurai like his father and become a merchant. Matsukichi deals with frequent cases related to store credit at Ikawa and is able to solve those problems.