The story takes place on the eve of the collapse of the bubble economy, and a white Christmas is coming quietly. In the early morning of Joto Third Middle School, a student's body was found on the pure white snow. The deceased was named Kashiwagi Takuya (Mochizuki Ayumu), a student in the third grade second class. His death made the newly appointed head teacher (Kuroki Hana) sad and panic, and the school felt unprecedented pressure. After the police's inspection and judgment at the scene, it was determined that Kashiwagi died of suicide. The original incident returned to silence, but several letters of accusation aroused new waves. The letter stated that Kashiwagi was bullied by his classmates Oide Shunji (Shimizu Hiroya), Hashida Yutaro (Kato Mikio), and Iguchi Mitsuru (Ishikawa Arata) before his death, and was eventually killed by the three. Since then, the media has repeatedly made malicious interpretations, and parents are excited, making this school no longer peaceful. As the class monitor, Fujino Ryoko (Fujino Ryoko) could no longer bear it, so she decided to organize a court in the school to find out the truth about Kashiwagi's suicide... This film is adapted from the classic masterpiece of the best-selling mystery writer Miyabe Miyuki.