San is a goblin from what we know so far.
Something happened to him tho that made him lose all his power and memories which is why the others have to take care of him so often.
704 is a reaper while San and Geumsun(blue hair guy) are goblins. Reapers have numbers instead of names. Goblins need yang energy from sex in order to stay alive so that's why Geumsun and 704 are fucking.
Ahhh! Thank you thank you!
Thank you thank you!
So 704 is a reaper and san is a reaper? So what is the blue hair guy? I love the story i just kind get confused (⌒▽⌒)