This story about assassins takes place in a fanciful world. Yim Mo, who used to have a prestigious nickname “Yama”, has caused his family to break up with fatal consequences due to his blunder. He ends up as a mediocre killer. He has facilitated the emergence of a formidable hitman called Kiu Sing, aka “Zero”. However, the duo’s destinies are rewritten because of a Taiwanese tycoon called Or Ching-hung. Yim Mo counts himself lucky as his buddy Yiu Suk-han, who is a hooker by profession, manages to bridge the communication gap between him and his daughter Yim So-chi. Unfortunately, Yim Mo’s life has become very difficult as an eccentric female assassin called Yik Lan keeps clinging to him. Kiu Sing opens a cafe as a decoy and hires a single mother called Chin Heung-sin. He also has a crush on Lam Sum-sum, who is a temple keeper with a mysterious background. Yim Mo and Kiu Sing are forced to engage each other in a duel as Assassin Hunter shows up.

Jacqueline Wong, a maid in the household of the Vice Minister of War, leads an alliance of maids at the six ministries, who trade information and make money together. Roxanne Tong sold herself to be a maid to raise money for her lover to travel to the capital and take the imperial exams. Jacqueline and Roxanne take care of the Vice Minister's first wife and second wife (Angie Cheung), respectively, and fight against each other on behalf of their mistresses. Jacqueline and the young master fall in love, but they are oppressed by his father. Timothy is demoted after committing an offense. Tony is determined to achieve honors from the imperial exam and restore the family's reputation. Lisa Lau, the daughter of the Minister of War (Pat Poon), sets her eyes on Brian and tries to seduce him. Jacqueline and Roxanne worry that they will lose their lovers if they achieve a high rank in the imperial exams, and vow to ruin their scholarly dreams. As the two pairs of lovers are about to break up, they get embroiled in a treasonous conspiracy.