This suspense drama set in the mid 1700's depicts the plan of the Tokugawa rulers to send a number of homeless men to a remote island Sado to perform forced labor. Living conditions on the island are terrible and the men soon become rebellious. Based on a short story by Seichō Matsumoto.
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 sister, in order to further his personal aims.
Kagaya bribes the vagrants' foreman to incite the men to escape, planning to have troops shoot them down when they arrive at the beach.
The plot fails and the desperate vagrants attack the guards. Kuruzuka crosses swords with Yaju and both die. The magistrate's office goes up in flames.
All vagrants are killed in the fighting except Senta who with Miyo, a young woman of the island, rows away in a small boat to a new life.