do you count harem as romance? For me harem is ok in a comedy but I don't really view it as romance, so the ones below aren't harem. Are you thinking straight forward romance or light-hearted?
Completed, may or may not be completely translated:
Straight forward, 24 chapters.
https://mangadex.org/title/21367/shunkan-gradation
half-hearted recommendation. Not a bad manga or anything, I just find it kind of bland, however romance manga is not my main reading so you may like it. I will probably read the remaining chapters. Completed, with only a few more chapters to be translated, translation ongoing. Have the feeling it was cancelled not really completed, but has positive comments.
https://mangadex.org/title/39524/landladyankee-my-apartment-life-with-a-yankee-landlord
I can only recommend this through chapter 33, for me after that it started to suck big time. The first 33 I found fun and it kind of has an ending in that chapter or the next.
https://mangadex.org/title/25862/pashiri-na-boku-to-koisuru-banchou-san
Not Completed:
If you don't mind slow and feel good this one is fun
https://mangadex.org/title/32648/sukinako-ga-megane-wo-wasureta
Funny, kind of a pre-romance, also a serialize version of it.
https://mangadex.org/title/36429/my-classmate-tanaka-san-is-super-scary-webcomic
Funny, kind of a pre-romance, girl tries to prank a guy but always fails.
https://mangadex.org/title/53421/doujima-kun-wont-be-disturbed