Ichiban Kasuga, a low-ranking grunt of a low-ranking yakuza family in Tokyo, faces an 18-year prison sentence after taking the fall for a crime he didn't commit. Never losing faith, he loyally serves his time and returns to society to discover that no one is waiting for him on the outside, and his clan has been destroyed by the man he respects most.

Ichiban sets out to discover the truth behind his family's betrayal and take his life back, drawing a ragtag group of society’s outcasts to his side: Adachi, a rogue cop, Nanba, a homeless ex-nurse, and Saeko, a hostess on a mission. Together, they are drawn into a conflict brewing beneath the surface in Yokohama and must rise to become the heroes they never expected to be.