Secret agent Jiro Kitami, who had infiltrated in Tonwan, was requested by the director of intelligence Sritai to steal a large amount of money that was hidden by Gegen, leader of the rebel guerrillas associate "Darkness". He was teamed up by two beautiful female agents, Miichin and Bai-Lan. The three arrived at Yokohama by ship in pursuit of the Gegen Gang, who earned funds through illegal gambling at the casino and prostitution at a local strip club. During the investigation Kitami met He-Qing Cai, a Chinese gangster from Hong Kong and leader of the Qing-Cai Gang. He is also the rival of his competitors because Gegen take the territory of Yokohama. Then they disguise themselves as sailors and board their ship to steal Gegen's money. However, there was no cash in the safe inside the ship, only a piece of paper with a text that looked like a code.