Tetsuya, a young yakuza, returns to his family after his adoptive father is wounded in an attack from a rival gang. In his battle against dishonorable enemies and corrupt yakuza politics, he makes an unlikely ally in a rebel cop.

Accused of being a spy for a rival clan by Nanbu Clan samurai who then attack him, the 'Lowly Ronin' barely escapes with his life after being shot. Nursed back to health by Yamaoka Daijiro, the one Nanbu Clan retainer that believes him, he must find a way to prove his inno-cence to the others. The two team up together to uncover the mystery and find out who the real spy is that threatens the security of the clan. Against all odds, the two master swordsmen must rely on all their skills to defeat a vast conspiracy and save the clan from being abolished.

At midnight, Yamabe, a killer, escapes from prison. Two years before, bribed by a narcotic smuggler, Yamabe killed a real estate broker. As he was being arrested by detective Negoro, the detective's bullet struck Sakuko, Yamabe's girl friend who attempted to protect him, and crippled her. When Yamabe was sent to prison, Negoro cared for her and they fell in love. Sakuko asked him to marry her, but Negoro was reluctant to take the killer's sweetheart from him. Learning of the relationship of his girl friend and the detective, Yamabe had pledged revenge.

The film is set in Karafuto after the radio broadcast of the Imperial Rescript on the Termination of the War. On August 15, 1945, Soviet forces invaded Karafuto. On August 20, the postal telegraph office in Maoka suspended operations and nine of the twelve telephone operators committed suicide by taking potassium cyanide while the city was being invaded.