The story of a detective agency that sniffs the incident and sets out to make a profit, but eventually works hard for justice. Nanase Goro, who is good at staking without sleeping and has been nicknamed "Nezumi", is a member of the Akatsuka detective agency. He is tasked with stealing a floppy disk containing confidential data from a pharmaceutical company and locating the criminal who threatened him, but he doubts the company's attitude and sets out to find out the hidden truth. Goro fell in love with Ranko, a beautiful woman involved in the case, but while protecting her, he discovered the fraud of the company over new drug development and solved the case brilliantly.