Woah. This is shaping up to be like a bastard-sweet home thing, where the author writes a happy ending for the first story, then does a 180 or a 360, but it's difficult to tell.
Hatsukoi zombie wasn't the best story I've read, nor the best romcom, nor even the best romcom harem. However, it had a lot of interesting ideas. This new work seems to be a bit more refined with its themes, and it also feels like it's been planned out better. I'm gonna keep my eye on it.