Responses
he most likely has OCD of some kind. his mother treated him so dismissively that he thought it was because he smelled bad, so he started obsessively scrubbing himself in the shower to keep himself clean
after meeting MC, his obsessive focus changed of course but you could still see him talking about his smell and washing his hands too much occasionally when stressed etc
ok but what was yoochae's sickness in gbe first place?? did they even tell us or is it just a vague throwaway plotline