A young samurai stuck at the bottom of the hierarchical order attempts to rescue his childhood sweetheart from an evil clan lord after learning of a plot to kill her and her infant child. Bunshiro Maki is a skilled swordfighter who's lethal with a blade, yet still can't rise through the ranks of the system. After his father is accused of plotting against his clan and forced to commit ritual suicide, his longtime love Fuku is sent to Edo to become the clan lord's concubine. A few years later, Fuku has bore the clan lord a son. When Maki learns that the clan has hatched a plan to kill Fuku and her son to secure succession to the throne, he recruits two childhood friends to help thwart the diabolical plot.