Devil Returns to School Days (en) is a dark revenge story about Kim Hyun-woo, a man who was brutally bullied in high school and later framed for murder by his tormentors. After his mother dies and he loses everything, he is mysteriously sent back in time to his school days. Armed with memories of the future and a ruthless determination, he systematically dismantles his bullies' lives, using psychological manipulation and violence to exact revenge. Readers enjoy it for its intense, cathartic power fantasy, the clever strategic takedowns, and the emotional payoff of seeing a victim rise up and destroy his oppressors.