Looking for drama with fairy tale components or small things which makes it a bit magical. For instance, it's common for korean dramas to have cherry blossoms raining in the romantic scenes. I'd like a drama with more of that stuff, not sure what, but maybe fireflies surrounding them or just something cute and out of the ordinary when the main couple is together. 

Anyways, just something that makes the drama feel magical.

Thanks :D

hmmm...not exactly what you requested, but every time I watch Secret Garden I get that 'magical' type feeling
Playful Kiss, she envisions her crush as some forest prince loool.. tho the reality is bit more awkward ;P 

& Dream Knight.. mini-drama so a fast watch, but with one of the best opening themes I've seen so far! xD 

Then there's High School Love On, about an angel accidentally turned mortal, becoming linked to two humans.. ♡♡♡
KBS 2TV special drama 'Like a Fairytale'

In 1990, Myung Jae enrolled in a major he wasn't interested after studying three years for college and spending meaningless days in class. But he fell in love with Seo Young at first sight and joined the singing club to be with her. But Myung Jae feels that Jung Woo, a golden boy majoring in dentistry, is a competition. At a club gathering, Myung Jae and Seo Young rode the duck boat and he extends a hand but she pushes him away. Myung Jae is devastated and that's when he's called to join the army. Meanwhile, Jang Mi is in love with Jung Woo. The two hold hands in the dark. He suggests attending the song festival with him. But Jang Mi's mother cuts off Jang Mi's hair so she couldn't attend the song festival. And her one-way love is over. In 1996, Myung Jae and Jang Mi who each failed at their first love, meet at a bank by coincidence. Is that reunion a lottery or lightning?--KBS World
Arang and the Magistrate
The snow queen, the storyline is just beautiful and it's really a masterpiece.
I definitely second Gu Family Book
I watched it recently and it's literally one of my favourite fantasy(magical) historical kdramas, since k-dramas usually don't have that many historical fantasies. This one was so beautiful and it legit has all the things u asked for, magical, mythical being, fireflies (blue ones in the drama) cherry (peach) tree. Beautiful story.

Another one that I would recommend but it's chinese historical fantasy wuxia drama. It's completely fictional set in the a world of magic, spells and power. But it's a beautiful forbidden love story. It's quite long but please consider.
If not defs watch gu family book