Boxer Kusunoki Sota, whose body was squeezed by many years of fighting, was forced to retire due to a doctor stop. Kusunoki decides to retire after marrying his lover, as he cannot abandon his regret and obsession with the fight. Kusunoki gets a job to build a new life, but he doesn't go well no matter what he does, and he spends hard days unfamiliar with society. Meanwhile, Kusunoki receives an offer from a mysterious man who claims to be a fan for underground martial arts betting a lot of money. Kusunoki took the invitation only once, but the excitement he had forgotten in the ring after a long time revived, and Kusunoki re-engaged in the world of fighting. The feeling of exhilaration was irreplaceable for him.