The Rule of Violence.

High school student Sung Jin commits suicide after being the victim of school violence for a long time. Three years later, one of his bullies Han Yeo Wool debuts as a celebrity. Sung Jin's brother, Sung Hyun, blames himself for not recognizing the pain his brother went through and finds a comment on Han Yeo Wool's news report that Sung Jin didn't commit suicide but was instead killed by Yeo Wool. The brother sets out to find the truth and he heads for destruction.