Daisuke Mizushima and his wife Akiko had one son, Yutaka. However, two years ago, Yutaka took his own life after being unable to endure relentless bullying. Since then, his room has remained untouched, and meals are still prepared for three, as Akiko struggles to move on from the loss of her son and husband. Into their grieving lives steps Masatoshi, Yutaka's high school friend, who arrives bearing Yutaka's handwritten suicide note. The letter reveals the name of the ringleader behind the bullying. Armed with this information, Masatoshi proposes a new plan to Daisuke. The story unfolds into a relentless pursuit of truth and vengeance, as the family confronts the past in search of closure.