Storyline

...It's been raining for days. In the rainy season of Marihamadai, which was hit by the heavy rain for the first time in 8 years, in the dull rain pattern spreading as if taking away the color of the city, One client visited the "Kibukawa Detective Office". "This is the Kibukawa detective agency, isn't it?" "...Um, I think there was a detective assistant named Sagishima here..." "No, no, it wasn't a daughter like you... was there, wasn't there? A young man called Shirasagisu..." The client says that he came to fulfill the "promise of 8 years ago" to a young man named Shirasagisu, who was once at the detective agency. While the heavy rain is hitting the window, the current detective assistant, Itsuna Shirasagisu, starts listening to the request to take over the request. A story about an incident 8 years ago that was taken on by a young man who used to work at a detective agency shoulder to shoulder with Ryousuke Kibukawa.