Hee Woo is a prosecutor known for his rather crazy methods. He starts investigating Cho Tae Sub, a man who wields the utmost power in the running of the country. During the investigation, Hee Woo realizes that he has died. However, the woman he meets after his death gives him a second chance at life and revenge.

Hee Woo goes back to living as a 21-year-old. He realizes that he can actually change the course of his life and does his best to live life to its fullest. Meanwhile, he keeps remembering events from his past life that he thought was unfortunate and changes their outcomes. Later on, Hee Woo goes back to being a law student.

Hee Woo settles into his life as a college student once more and gets started on his revenge against Cho Tae Sub in earnest. He seeks out teachers to help him get ready for the long-term fight that lies ahead. In the process of doing so, Hee Woo meets an elderly gentleman, known as the master of auctions.

Hee Woo continues to keep a close eye on Cho Tae Sub’s actions. One day, Min Soo introduces Hee Woo to a friend of his who has a brilliant idea. Sung Hwan is a former med school student who has now developed an idea for a smartphone application. Knowing that this will benefit Cho Tae Sub if he doesn’t step in, Hee Woo decides to help Sung Hwan.

Hee Woo helps change the life of Sang Man and his dad before he goes off to serve in the military once again. Seven years go by, and Hee Woo returns as a prosecutor. However, he volunteers for a position at a small country branch office instead of Seoul. As he starts to look into local crimes, the name of a gang continues to grab his attention.