As someone already mentioned here, it's literally one of the rare gems of K-dramas. The series has everything that's necessary for romcoms and K-series in general:

✓ Great from start to finish
✓ Green flag main characters
✓ Interesting plotline
✓ Happy ending
✓ Suitable cast for the characters
✓ Focus on main characters with minimal focus on side characters
✓ Beautiful OSTs (Sonagi and Spring Snow!!!)
✓ Green flag second male lead
✓ Many more things I probably forgot to mention

It had many emotional scenes, but overall it wasn't depressing at all, so it's perfect if you want to watch something to feel entertained and feel like you're a teenager again, kicking your feet, lying in bed giggling, and blushing out of adoration for the characters.

literally 10 out of 10