Hasumi Mitsuko (Gaku Hamada), the ace of the Criminal Division of the Sakuramachi Central Police Station, rushed to the scene immediately after hearing that the suspicious man refused to be questioned and ran away. He calmly persuaded the man holding the hostage and was only one breath away from surrendering... At this moment, suddenly, a man dressed like a gangster wearing a double-breasted suit and sunglasses broke in! He subdued the suspicious person with skillful movements. The man who calmed the situation in an instant was Kagawa Eiji (Hidetoshi Nishijima), who was transferred to the Criminal Division. He was a detective uncle who was transferred from the Organized Crime Countermeasures Department of the Main Office, the so-called "Marubo (the common name for "gang countermeasures investigators")"... At this time, the housekeeper who worked at the university professor's house was stabbed. Eiji and Mitsuko teamed up to investigate, and during the investigation together, Eiji felt a sense of disharmony with Mitsuko, who was perfect in everything...! ? Under such circumstances, the two began to take care of the newly appointed detective Mizuki Nao (Moeka Kamishiraishi), but in fact Nao is the daughter of the deputy director of the Metropolitan Police Department-! ?