In the early summer, two violent incidents occur in Tokyo. One is a murder case called "Mad Cook", and the other is a continuous arson murder case called "Pyromania".

The detective of Suginami station, Koichiro Hasegawa (the protagonist) is on the case for the investigation of "Mad Cook" and "Pyromania" cases with detective Niko Nishitani, who has been dispatched from the main office.

Based on the scenario created in the program "D's Garage 21", this story is in charge of supervision from the original author Joji Iida. The scenario that spans 900 sheets of manuscript paper results in over 20 different endings being produced.