Healer. The lead girl has a crush on the lead guy other identity. Just watch it, its a brilliant drama ranked 2 (been in 1st rank for a week or two after it was completed) and ranked one in popularity. It's not overrated, its just the drama that we are wishing and imagining for.. You will never regret it unless its not your cup of tea. (Seeing your drama list, i think we share some interest in a drama though you dropped Secret Garden, my top fave and currently rewatching for the nth time)
Crazy Thing Called Love. It's not a drama nor Korean but the lead girl, a high schooler has some very cute one sided love with the lead guy. It's a Thai movie.
High School Love On. A cute High School love story. She had some feelings for him but she didn't know it and how to deal with it because she's an angel turned human.
i was going to suggest You're All Surrounded, You Who Came From The Stars , My Girlfriend is a Gumiho and You're Beautiful as well but you watch it already. Ahahaha..