The beautiful mystery buff Umizuki Chinami and career elite has been assigned to the Tokyo Metropolitan Police Department’s First Investigative Division as a rookie detective. However, on her first day of work, she is told that she is not in their future plans. Chinami ends up partnered with the handsome detective Shitara Kyosuke who has a black belt in karate. The First Investigative Division’s ace, Kyosuke had a promising future until he winds up having the blundering Chinami as his partner. Even though the two of them are scolded by veteran detectives and made to feel like a burden, this curious duo confront and solve difficult cases, and save Japan. ~~ Based on original work 'Senryokugai Sousakan Hime Deka Umizuki Chinami' by Nitadori Kei.