Surviving romance(don't let the name deceive u into thinking it have romance.....)
Maybe not a full on zombie story but "Nyaight of the Living Cat". Got the same concept as a zombie story except the zombies are cats. I dont think it got romance but its only one vol.
https://www.mangago.me/read-manga/nyaight_of_the_living_cat/
also "The Walking Cat - A Cats-Eye View of the Zombie Apocalypse"
the title kinda describes it. havent read it but i heard its good
https://www.mangago.me/read-manga/the_walking_cat_a_cats_eye_view_of_the_zombie_apocalypse/
Zombie 100
zombie apocalypse stories(no romance)
And pls don’t recommend zombie 100