university /collage dramas

First  dramas that came into my mind were  C-drama "My Sunshine" and also TW drama "The Way We Were" which had episodes mostly in their university days.  Also They Kiss Again (but this is a sequel so you must watch It Started With A Kiss first), Meteor Garden, Hi My Sweetheart,  Hot Shot,  MARS,  In A Good Way (have yet to watch this but know thru the synopsis)

Mostly flashbacks:
My Best Ex-Boyfriend
In Time With You

I mostly watch Chinese and Taiwanese dramas that's why my recommendations came from them haha!  The first two are probably the perfect embodiment of  what you're looking for but the others aren't so bad as well :)

Heartstrings is about university students who are music majors
Reply 1994 is centered around university students

There's also What's Up, which is about the students of a university musical theater department.

Heartstrings - Yonghwa from Cnblue and Park Shin Hye ;)

Thank you : )