beta
Ok so I re-read it, and it's possible for him to have a happy ending.
If the flashback he got (from when he passed out in chapter... 14? Around that) was real, and he actually had a family -- then it's possible for him to stay there.
There was a theory that Seong-ah had a brother, and if that brother theory is real - and that brother is already dead, then it's most likely that he'll be able to stay there.