本剧改编自同名漫画，讲述了了作为经营非法工具的“工具商”踏入池袋地下社会的不起眼大学生，在黑道、半腐败集团、中国黑手党等非一般坏人中间生存的样子，时而幽默，时而紧迫的新感觉犯罪悬疑故事。

Tomio Shiraishi graduated from a prestigious university and now works for foreign securities company. He has a beautiful fiancée, Kozue Aoike, and no complaints with his life. One day, his father kills himself, leaving behind large debts. Tomio Shiraishi is liable for his father's debts. He pays what he can with his savings account, but it is not enough. He is chased by moneylenders. Tomio loses everything. His job, fiancée and savings. He then becomes homeless.

Tomio Shiraishi then decides to work for Daisuke Akamatsu, who runs Akamatsu Finance. Akamatsu Finance is the company that drove Tomio Shiraishi to become homeless. The company looks like a normal finance company, but it actually lends money with high interest. Tomio Shiraishi decides to do anything, including illegal acts, to make money.

Inami and Tamaru work at the Public Security Mobile Investigation Unit Special Investigation Team, a team made up of specialists with different expertise. Inami tackles criminals with showy maneuvers, while Tamaru corners criminals with cool calculation. Together, the team tackles terrorists, new religious cults, military spies, secret narcotics organisations and complicit politicians.