On the night of the typhoon, Hideaki Fujisawa, a mathematics teacher at the private Seiran Middle School, fell from the teaching building and died. The police determined that it was an accident. However, his student Mao Asakawa felt that something was fishy. Teacher Fujisawa's abnormal behavior during his lifetime convinced her that this was not a simple accident.
As the investigation deepened, Asakawa Mao discovered that the death of Teacher Fujisawa was inextricably linked to a student suicide in the class fifteen years ago. The classmates Kenta Sato, Nao Suzuki, Kosuke Tanaka and Kaoru Kobayashi seemed to be deliberately hiding something. Their secrets were like an invisible net, involving everyone.
As the truth gradually emerges, a past story about campus bullying, the sin of silence, and the redemption of human nature is revealed. Everyone is struggling in this entanglement that spans fifteen years. Their choices not only determine their own destiny, but also make people re-examine the complexity and darkness of human nature. In this belated trial, who can get real redemption?
