A poison master who'd rather die than let his sister be forced into marriage decides the solution is to marry a random woman himself, and then actually falls for her. The show commits to the bit: every poisoning attack doubles as a love confession, every combat scene is foreplay, every joke lands because the emotional stakes are real. You watch a hardened killer learn that vulnerability is not weakness, one terrible pickup attempt at a time.

Hikaru Gero grew up in poison and shadows. As heir to one of the Five Great Families of assassins, he has spent his whole life in the underworld with no thought of love or marriage. That changes when the head of his family decrees that his sister will be made to bear an heir, whether she agrees or not. Determined to shield her, Hikaru meets Mei Kinosaki, a gifted marriage swindler who also happens to be his current target. Seeing marriage as the only way to settle the succession problem himself, he asks Mei on the spot to help him find a bride. With the con artist as his advisor, the elite killer takes on his hardest job yet: getting married. It's action wrapped in comedy, murder wrapped in romance, with drama along the way.