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 doing everything in her power to search for Shinichi, Ryoko is ordered to go undercover and investigate her.Ryoko disguised herself as her secretary and infiltrated the mansion of the Hanaoka-gumi, the head of the drug trade.However, there she has a nightmare reunion with Shinichi.Ryoko makes up her mind to put herself out there, trying to force Shinichi to wash his feet before he gets tainted by the organization.