Ryoko hides her identity as an investigator and remarries, but her son-in-law, Shinichi, refuses to accept her and runs away from home. One day, while trying to find Shinichi by all means, Ryoko is ordered to go undercover. Ryoko disguised herself as a secretary and infiltrated the mansion of the Hanaoka-gumi, the head of the drug trade. However, he has a nightmare reunion with Shinichi there. Ryoko decides to put herself in order to get Shinichi to wash his feet before he gets tainted by the organization.
