4. Crash Landing on You 

5. Eccentric Chef Moon (I think the ML was the one having a hard time, not sure.)

i could only think of a movie, but because it is stated as drama, then i'll put it here as a bonus 

Teacher's Diary (synopsis : Song, a washed-up wrestler with a broken arm  takes a job as a teacher at a rural school on a houseboat and finds himself feeling lonely after he's cut off from such modern conveniences )

More than a day, so new topic:

10 in which the main couple are deskmates in high school. 

Added: Or they may be classmates who sit close together.

1. Our Beloved Summer

2. Cross Fire

4. Cherry Blossoms After Winter - though it is not shown for long

If they sit behind and in front of each other, or are diagonal from each other, does that count?

I'll change to close proximity since the topic seems to be lagging.

6. The Eclipse - it hasn't been airing for long, but they've been sitting next to each other for all the episodes until now.

7. Bad Buddy

9. In Your Heart (2022)

10.  First Love Again (c- drama)