For centuries, the deadly arts have been perfected by Masters, and Five Great Families hold the greatest power and influence. Hikaru Gero, an heir to the Gero family, lives in the underworld as an elite assassin. When his sister is pressured to produce an heir, Hikaru asks Mei Kinosaki, a brilliant marriage swindler, to find him a bride. The most challenging mission of his life begins!

Hikaru Gero, an elite poison assassin from a secretive clan, enters an unfamiliar and terrifying new battleground: the world of modern dating. ...

When his ruthless family threatens to force his younger sister into an unwanted marriage to secure their clan's lineage, Gero decides to act. Lacking any romantic charisma, he rescues his latest target—a brilliant marriage swindler named Mei Kinosaki. In exchange for life and protection, Kinosaki agrees to serve as Gero's dating coach, transforming a lethal hitman into a charming suitor while guiding him through hilarious and chaotic matchmaking encounters.

Together, the unlikely duo navigates dangerous bodyguard missions, rival assassin guilds, and deadly underworld conflicts while searching for prospective brides. As Gero defends unique allies and battles formidable enemies, he discovers the true meaning of companionship. Blending high-octane action with lighthearted romance, this intense fight for love tests if a seasoned killer can successfully complete his hardest assignment yet: securing a genuine, happy marriage. More+