My Lovey-Dovey Wife Is a Stone Cold Killer Vol. 3 (manga)

SO CUTE YOU MIGHT JUST DIE!

When a cryptic text with a call for help drops into the assassin family group chat, this lethal family (and harmless husband-in-law) are quick to assemble. Arrangements are made, and soon Setsuna and her husband are making the long and complicated journey to the assassin ancestral homestead. With sister Haruka in tow, the trio isn't entirely prepared for what awaits them at home...