Most of the manhwa I've read so far has been Tokyopop, actually, so I'm wondering if the traits I think of as 'Korean' are instead a house style from a particular publisher? Something about the style of the eyes, the liquidity of the line, and the solidity of the line - less wispy, and with fewer breaks in it. Although I'm seeing that in Antique Gift Shop, too, which isn't Tpop, and ISTR it being in Thousand and One Nights, which isn't Tpop either.

Snow Drop and Threads of Time (along with the gift shop) have that eyes-and-lines similarity going, I think - I'm at work and can't double-check (and I think I ended up selling Snow Drop to Half-Price Books after I got bored with the story). Demon Diary ... I can't quite recall. I'd have to look at it again.