Meet Cha Eun-jin, who is a bit of an anomaly in the Korean criminal underground. This scrappy 26-year old, orphaned and separated from her older sister when she was still a child, has fought her way up the food chain to become the leader of her own gang. Known in mob circles as Mantis, her skills in hand-to-hand and weapons combat are unsurpassed, and anyone who crosses her can expect a beating, her own men included. Having grown up in such a male-dominated and violence-prone environment, Eun-jin has adopted a tomboy lifestyle, walking, talking, and dressing like a man. However, this is all turned upside-down when Eun-jin finally is reunited with her long-lost sister. Unfortunately, she is dying from cancer and asks a favor of Eun-jin: to get married and settle down. So what does the legendary gang leader do? She sends out her men to find a husband for her, as quickly as possible. Of course, this is easier said than done. Though they hire a professional to give Eun-jin a makeover and give her dating lessons, this ends up backfiring as she keeps lapsing back into gangster mode. Finally, Eun-jin settles on Kang Su-il, a civil servant who has no idea what is going on most of the time. Seeing Su-il as the quickest way to fulfill her sister's dying wish, Eun-jin gets hitched, which is when the fun really begins, as she tries to play housewife to the clueless Su-il while continuing to run her gangland operations. Unfortunately, matters are complicated as the leader of a rival gang tries to muscle in on Eun-jin's territory. And if that wasn't enough, the dying sister makes one more request: for Eun-jin to become a mother.