Long Quest Involving Romeo & Juliet

Only wedding village i know of is in Amoria, which i doubt it the case due to amoria not being out in all versions.

check strategy wiki, click the guy and see if ther'es a map accessible option.

The only guy that seems similar to that name is the guy under Zenumist HQ

Allegro is indeed in Amoria. Amoria and Magatia were released at the same time in KMS, so they tied the two areas together a little. The only concern which I'm not sure of is if GMS Allegro works for the quest.