Joo Hong Bin, the CEO of a game company, has got everything. He is capable, rich and even good-looking. However, this perfect guy lacks in one thing. He is so ill-tempered. The worst guy on the planet. One day, this supercilious guy turns into a monster. When it rains, he becomes furious and some blades are coming out from his body. Se Dong, a woman with a bright personality and Chang, his first love's son appear making him confused.
Joo Hong Bin has anger management issues, and relies on his faithful secretary to keep him in line. Se Dong is a game developer who finds that her company has been sold to Hong Bin without her knowledge.
