Kang Si-woo is sent to prison due to a certain incident in the past. After being released from prison, he joins hands with Do Ji-hyuk in order to take revenge on Kang Ha-joon who ruined his life. Kang Si-woo has only one purpose. 'To make Kang Ha-joon feel the same as he did' but the more he hates him, the more Kang Si-woo gets caught up in the past when he use to like Kang Ha-joon and starts to gets caught up in a sense of self-doubt and guilt every day. It's getting more and more catastrophic...!