mc keeps accidentally walking into the other world (which we now know is because ahjussi is very interested in him + corrosion with machinery).
as for ahjussi, he’s a plant-like creature (he’s part of a “deep flower” species i think). there seems to be a thing where his species has specific times to procreate? i think its the harvest im not sure. but i think thats where the smuts gonna be LOL
all the other world creatures (residents) look like humans, at least initially, when humans walk in. the creatures seem to really dislike machinery because it causes their worlds to overlap, which is caused by bugs laying eggs that emit a special frequency. seems though they can also communicate through dreams. theyre also very particular about exchanges and payments, which is why ahjussi (and others) keep telling the mc he’s stupid for taking things from other creatures. the otherworld itself seems to not really care about humans, since they’re weak, but there seems to be “hunters” and i think theure related to arresting creatures that eat humans but we havent reached a real explanation for them.
then there’s the cafe owner, a human who’s been messing around with the other world. its implied that he’s stealing a whole bunch of stuff, ie the pages of that book and the eyeball. probably why he has that powder to remove the residents’ smell. we dont know exactly why hes doing that yet, but he is shoving it all onto the mc lol
long af explanation but thats what i got!

A kind soul to explain to me i am having a hard time understanding the plot ╥﹏╥