Yukiko Makabe (played by Yuki Amami), the former director of the Special Crime Investigation Department (SIT) of the Metropolitan Police Department, was transferred to the emergency case corresponding interrogation class of the Investigation Division 1 due to work. After a period of running-in with uncles such as Kajiyama Shengli (played by Tetsuji Tanaka), Hishimoto Susumu (played by Dot Dot), Nakata Zenjiro (played by Osugi Ren) and Koishikawa Haruo (played by Kohinata Fumiyo), they gradually developed a trustworthy comradeship from the initial quarrels. During this period, the clown partners of the Investigation Division 1, Daijiro (played by Suzuki Kousuke) and Tetsuji Watanabe (played by Hayami Naomichi), were reluctant but gradually integrated into the atmosphere of the interrogation class and became another vital force to overcome the psychological defense line of the suspect. In the fast-paced society today, the world is in decline and people's hearts are not as good as before. The opponents faced by Yukiko and others are becoming more cunning and better at hiding their murderous intentions...