[TOMT] Korean romance movie (maybe comedy too?) about a postal worker

a few yrs ago i was on an 18 hr flight and the person in front of me was watching a kdrama and i was lowkey invested. i wanted to find it again and watch it for myself but i barely remember anything. here’s what i do remember:

the movie poster i want to say was mainly yellow or mainly blue (this could be wrong). it involved two people who liked each other i believe, and the man was a post office worker. the man also lived with his sister. there were often examples of texting and itd show the chat bubbles on screen. i watched it on a flight from the movies they provide, either american airlines or united, in 2023.

i know this isnt much to go off of so im honestly not expecting anyone to recognize it lmao but it’s bothered me for a while. ive tried searching everywhere. thanks!