Just based off cute/lightheartes and in a school or office setting I can think of a few
Psuedo Harem
Love is hard for otakus
That girl is not just cute (gets better as it becomes serialized later on)
An observation record of my fiance a self-proclaimed villainess
Akward senpai (these are just short snippets not rly a whole manga)
Insomniacs after school
Ore monogatari
Kimi ni todoke
however all of these are very different with regard to the pacing setting and themes even though they're all romances in a school or office that I recommend...so try em out
I also have some other great romance manga that are outside of these settings depending on what you are looking for as well as other manga similar to those above.
Another thing you could do I just thought of is to search those tags then filter by best rated though you would probably find a mix of drama and light-hearted. In anycase enjoy