Tune in for Love (2019)

Both movies has very similar plot.
Which is the leads meet each other end up liking each other but one has to leave and over the years they reunite.

Similar vibes of a young couple going through life together and the struggles that come with it.

The missed opportunities to be together subplot, the color grade effect, "subtle" romance. Good dialogue, but not so dramatic

Both movies show 2 individuals reconnecting during different periods in their life. Although past lives is a more evolved take on this topic, tune in for love is a nice watch if you're looking to feel something but not with the same baggage

This movie is the first one that came to my mind when I was watching 20th CG.
It has that 90's vibe too with a broadcasting theme. Also has the email form of communication.
Coming of age, young love, nostalgic feels and Romcom.
There's also a separation period, multiple actually, but they always found eachother.
This has a good ending.
ML is Jung Hae in too, if you're a fan.