Park Sunghoon is the CEO of one of the most successful technology companies in Korea. But he was accidentally involved in a scheme, and to save himself he had to marry the son of the most feared mafia, NNishimura Riki, who was the most fierce killer amongst the young mafia generation.

Sunghoon was against of the marriage, and he was always rude and arrogant with Ni-ki but he was nonchalant and ignorant about Sunghoon's behaviors. But little did Sunghoon know that Ni-ki had fallen in love with him and now he was possessive about him.

One day, Ni-ki is tasked to find out a druglord who had visited a V.I.P. club somewhere in Korea. Instead he finds Sunghoon in that club with someone else and they were too close for Ni-ki's liking.

He immediately forgets what his mission was.

(You, Ni-ki, start)