Kazama Ayato is a young man who works day and night while paying off the debt of his deceased father and caring for his mother, Asami, who suffers from an incurable disease. His younger brother, Sohei, was also responsible for repaying debts and caring for his family while practicing martial arts every day and started following in his father's footsteps. Despite being devoured by a stifling life, Ayato wants to find a small happiness with his lover, Hinata. However, on the night of the banquet celebrating the marriage of Ayato's best friend, Yamato, their modest daily life is taken away by unexpected violence.