Yoon Jae-yi, a professional killer who is nicknamed 'Mimi', a crazy sashimi because he slaughtered people with sashimi like crazy. After losing his step-brother Jung-woo a few years ago, for him, life is nothing more than an immortal life. Then, a newcomer 'Go-won' appears, who gives him an unusual headache with his appearance, skill, and mindset. “Your eyes… you are beautiful.” 'What is this madman?' A terrible relationship begins between a professional killer who is afraid of love and a rookie killer who hits his goal.