Here are my recommendations. They are all light hearted and fluffy dramas.
1. Fall in love
2. Love o2o
3. You are my glory
4. Flourish in time
5. Perfect and casual
6. My little happiness
7. You are my hero
8. A little thing called first love
9. A love so beautiful
10. The day of becoming you
11. You are my hero
12. I hear you
13. Le coup de foudre
14. Love scenery
15. Lovely us
16. Sweet teeth
17. Put your head on my shoulder
18. Crush
The below dramas are not romance related. But I loved it, so you can try these.
19. The prince of tennis: Its about tennis and the leads are all in high school. I loved this drama.
20. The King's avatar: Its similar to falling into your smile cause of the e-sports genre. But this drama is fully based on e-sports.