Death-row inmate Sudo sends a letter to magazine reporter Fujii. In his letter, he states that a man named Kimura, also known as "teacher," committed numerous murders for insurance money. While checking out the story, based on Sudo's tip, Fuji becomes convinced that the letter is correct. But, a lot of time has passed since the incidents and Sudo's testimony isn't clear. Due to the persistence of Sudo, who is a former yakuza, and Fuji, the police begin to move. ~~ Based on the nonfiction novel "Kyoaku-Aru Shikeishuu no Kokuhatsu" by shincho45 editorial department (published October 28, 2009 by Shinchosha Publishing Co, Ltd).