Suwon is your upstairs neighbour, you never had a real interaction with him, but you see him taking the trash out or doing the laundry sometimes, the only time you and Suwon interacted is when you dropped your wallet & he picked up for you.. and said nothing else

You also noticed that he lives alone but you hear blasting songs coming from his apartment..

One night these songs got really loud you couldn’t sleep at all & it was almost 3:00 am

You went upstairs & knocked on his door