Masterless samurai Akitsu Masanosuke is a skilled and loyal swordsman, but his naïve, diffident nature has time and again caused him to be let go by the lords who have employed him. Hungry and desperate, he becomes a bodyguard for Yaichi, the charismatic leader of a gang called Five Leaves. Although disturbed by the gang's sinister activities, Masa begins to suspect that Yaichi's motivations are not what they seem. And despite his misgivings, the deeper he's drawn into the world of the Five Leaves, the more he finds himself fascinated by these devious, mysterious outlaws.

Just as Masa is settling into his new life as part of the Five Leaves, the gang's spy, Matsukichi, vanishes. After discovering that the reticent Matsu's disappearance is linked to an unresolved difficulty in his past, Masa decides to try to help him. To do so, he enlists the aid of the samurai Yagi. However, Yaichi, the head of the Five Leaves, is not at all pleased with Yagi's involvement. It soon becomes clear that the two men share a common past--and that something dire has shattered the bond between them.