I have a feeling Hajin did it in case the guy tries anything shady/locks the door
Or Chunghoon (the gray-haired guy) put it there so someone like Hangyum would find them there like that.. idk.. ┑(￣Д ￣)┍
It's pretty messed up either way the game Chunghoon is playing..
I am 99% sure it was Hajin that put the slipper inbetween the doorway. Why? Hajin is wearing blue pants while Chunghoon is wearing white. When the slipper is placed you see blue pants. Another reason Hajin is following behind Chunghoon as he enters the room. I think he may to have intervention if something happen maybe not meaning Hangyum because he has been keeping the situation away or he knew Hangyum would be close behind him to save him if something would happen. I could be wrong.. Just my guess.
Wait so who placed the slipper inbetween the doorway? Why? Or was it just so white haired seme could catch them for plot purposes?