i did the quest in the san region. the thing was, i intended to not do the quest, but somehow it turned out that i got two of the items just because i fought at the beach a lot, and the skull... a guy i didn't know who already had a sj found ghouls near the beach, invited me to his party, practically killed the ghouls himself, and the second ghoul, i got the skull o.O
amazing luck, ne? heehee.