Yukiko Miki, the only daughter of the Yamako-gumi, a yakuza group in Kansai, begs her father to let her start a company, and with three henchmen who also act as bodyguards, she establishes "Gokiburi Shoji" (Cockroach Trading). Their business involves committing crimes such as bank robberies to make money, and Ryotaro Anzai, who approaches her without knowing she's the daughter of a yakuza, also joins the company. Initially, they plan to rob an armored car, but a father and son duo steal 500 million yen from them. Next, they plan to rig a boat race, but by chance, Ryotaro spots the man who stole the money. Changing their plans, they devise various schemes to get 500 million yen back from the father and son duo.