A serial explosion occurred in Tokyo. Hayashida Toranosuke (played by Hiroshi Mizushima) and his boss Nihara Tomomi (played by Teruyuki Kagawa) of the Metropolitan Police Department's Investigation Division 1 arrested a strange man, Ryuusuke Kyuju (played by Takuya Kimura), who was suspected of being a suspect. In the Metropolitan Police Department, Ryuusuke used his meticulous reasoning ability to quickly find the real criminal, which surprised the two. It turned out that Ryuusuke was the new director of the Brain Science Department of the Scientific Police Institute (IPS). Five years ago, he was still working in a nightclub, but due to an accident, his right brain became abnormally developed, thus becoming an excellent brain scientist. In the IPS Brain Science Department, Ryuusuke led his only assistant Yuri Kazune (played by Haruka Ayase) who was transferred from the Chemistry Department in a unique way, and assisted the Metropolitan Police Department in solving many seemingly incredible and difficult cases. This drama invites celebrity guest appearances in each episode, including Hirosue Ryoko, Ichikawa Ebizo, Gackt, Kamenashi Kazuya, Nakama Yukie, Katori Shingo and others.