In 1802, vagrants are rounded up in Edo and sent to Sado Island for forced labor in a mine. Among them is handsome Yaju who was falsely charged with a crime by Kurozuka. Kurozuka arrives on Sado Island as an official under the new magistrate Shuzen, and makes repeated attempts on Yaju's life. In this he is helped by Kojuro, an ambitious constable who is willing to do anything for promotion. Kojuro finds out that Shuzen is suspicious of the prosperity of Kagaya, a mine owner and informs against him. Kojuro places his mistress Rin in the service of bachelor Shuzen pretending that she is his sis...