[Sora, please go to the Castle portal room and meet some guests? They should be there within ten minutes and will have a lot of shopping they need to get done but can't do for themselves.] Cain sends in Guild chat once the Elder confirms that she can indeed create a portal.
"Now, once it's connected, are there restrictions?"
"More than a few. But the most important ones are that only living creatures that have come from this side can return through it, so it can't be used to abduct anyone, and the Youkai at the other end must welcome you before you can fully exit the portal. Until then, you must remain touching it. If they reject you, you'll be sent back home."
"So it's limited to Youkai visiting friends? That explains why it never caught on for general purposes." Laura giggles, and the Elder smiles.