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.