I just finished With You and I know I could just browse the high school or first love tag but I'd rather get recommendations of your faves. What I liked about With You is that (until the angst-filled finale) it was just this slice of life friendship centered drama where we got to watch the relationship between the leads grow. Even though neither confess its sort of generally accepted by both the lead characters and those around them that they are a unit, they make no secret of wanting to stay together and of being important to one another. I liked that they didn't make a production out of physical closeness, the characters got to be near each other and casually touch one another without it being a big thing. Unlike a lot of dramas which try to drag out the will they won't they aspect to the point of frustration I didn't find this drama frustrating (until the finale). 

Something in the Rain (while not a high school or first love drama) had a similar feel in terms of relationship growth, where they're kind of dating but not really, both like each other and aren't really hiding it but aren't really talking about it either (this drama is on hold because it started to take a frustrating turn, but it was really great at first). 

Fight My Way | The characters feel like a unit throughout the series, even before they officially get together. They were childhood friends and ML was FL's, first love. This is a wonderful series about understanding that dreams don't have to end because you grow up. It's about falling and standing back up with the support of those around you.

Come and Hug Me | This is a darker series but with tons of sweet moments between the characters. The leads are childhood sweethearts torn apart by the deeds of a serial killer. This series ends this week. Highly recommend it!  

She was Pretty | The leads are childhood friends and each others' unspoken first love. They reunite as adults. ML starts being somewhat of a jerk but it gets a lot better. 

Weightlifting Fairy Kim Bok Joo | Just a good feel series about childhood friends reuniting in university. The leads feel very natural together, so you can't help but see them as a couple even before they confess their feelings.

In addition:

  • Hi School Love On - fantasy drama that is just adorable despite the male lead being so green n the acting the department.  
  • Love O2O - college drama that really has one of the most easy going dating life in dramaland.
  • Reply 1997 - straight forward story about friendship and a case of romance between childhood friends.
  • Just Between Lovers - probably more like something in the rain where in the leads in the leads in a some type of relationship, dating but not really, but most people around them already got the message of their relationship, though this one with underlying traumatic narrative
  • Plus Nine Boys  - not the first love type or highschool drama, nor the some dating type. but the relationship of friendship-romance between the leads is quite interesting
  • 15 years of migratory birds - probably most alike with With you, but sadly had a tragic end