The historical novel series depicts Heizou Hasegawa, who metes justice on wrongdoers and supervises the crackdown on arsonists and robbers in Japan's Edo period (1603-1868).
A robbery at Shop Yamadaya left 17 people dead. From the "Kitsunebi" note left at the scene, it was clear that it was by the Kitsunebi clan. However, its leader has passed and his successor is a former lover of Omasa. As a former member of Kitsunebi, Omasa suspects that they were framed by a criminal.