The Brothers, Kohei and Shuhei Mikami were abandoned by their father, after the mother passed away years ago. The intellectually disabled Shuhei is working in a factory, where he is violently abused by the manager on a daily basis. When Kohei finds it out under unpropitious coincidences, he kills the man in affect and deprives money. He buries the corpse in the mountains with his younger brothers help. During the criminal investigation is it Shuhei who soon draws the attention of the Detectives on the Mikami brothers through his diffus behavior and words. Even through he is unable to comprehend the murder of his older brother and doesn't understand the situation, the Police uses Shuhei as deciding factor in arresting the culprit.