The dungeon is in Korea, but as an esper with a pretty specialised power niche Haru is used to occasionally having to go international for these dungeons, and the fact that he already speaks Korean is definitely a bonus. The espers he's going to be working with are all in Quasar Guild, which is the largest one in Korea and which has just recently acquired a very powerful teleportation esper, one whose power can be stored in batteries Quasar also happened to already have in its possession, so they're covering the teleportation cost for Haru to get there.
"What's the point of being filthy rich if I can't even teleport to Japan with my boyfriend to meet his family?"
"I hope Woo-young enjoys the fruits of being the backbone of the transportation infrastructure of the Korean elite."
"I'm sure he's not the backbone of it, we had teleportation before Min Woo-young showed up. ...it did become a lot cheaper, though."
"Teleportation's less available in Japan and even more dramatically in North America for casual use, though maybe what I'm seeing here is actually just a difference in what price tag causes you to act less than casually and, across the ocean, what distances tend to be involved."
"North America is really, really big, and really a lot less dense... But I don't really go there unless there's a dungeon to clear, so I don't really know what it's like. If there's a dungeon that needs me specifically in North America Juno always used to cover the cost."
"Yeah, you're much more prone to being needed specifically than I am. Nobody ever needs to pay to haul me to Vancouver, so they don't."
"Seems like the world is under some misapprehensions about how amazing you are."
"My all-around personal amazingness doesn't make my powers more essential for any dungeons! Anyway, where are we going for dinner?"