'Monster Cop' Ma Seok-do investigates an illegal online gambling business led by a former STS Baek and an IT genius CEO Chang. Ma proposes an unexpected alliance to Jang and begins hunting down the criminals.

Shin-ah, a free spirit, has an unexpected encounter with Dong-gi, who seeks excitement. After a passionate night, she breaks up with her boyfriend and reunites with Dong-gi when he calls. The two fall madly in love.

Despite their different family backgrounds, four friends grew up together in the wearisome years of the 70s. But as time goes by, each of them takes a different life path.

Tae-sik, a troubled middle aged man and Sang-hwan, a troubled youth will meet in the ring with their respective mission. To change their life.