Two friends in the past were victims of serious school bulling. One could not resist his trauma, and becomes a serial killer, walking in the path of revenge. Another one tries his best to overcome the trauma and becomes a police detective. He now faces tragic fate to risk his life to capture the serial killer.

Park Ji Hoon uses his intelligence to protect his friends and fight back against the violence that takes place both inside and outside of his school

Both about student life
Blackout is more about past, while Weak hero Class one tells about the present and how friends change overtime

When a member of a clergy winds up dead, a temperamental priest and a detective team up to solve the case.