7-dai Tatarimasu no de Hayaku Kekkon shite Kudasai!

It is said that cats will haunt the family that killed them for seven generations.　

Kuro, a black cat who has fallen into the role of a "curse god," is trying to return to being a "god of fortune" by completing "seven generations of curses". However, the sixth generation is our protagonist Koutarou Nishikori, and he's hopelessly single, stuck pining for his mysterious first love. As it turns out... that first love is Kuro.