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.
So long as he's with Haru everything is good.
"—I meant to tell you and forgot. The thing you suggested, about asking if people were comfortable being pinged by my powers, that went over well. And I didn't really feel tempted to do anything more."
"Mmhm. I'm still not entirely sure what to tell people that I've worked with a lot before, though; your suggestion was a good fallback but it does leave the impression that I'm kind of incompetent for not having noticed it in all these years..." The ways in which Jaeha is incompetent are unrelated to that.
"I don't think it's necessarily going to be hugely alarm-raising for most people if they realize that you were doing it all along and just decided to start being more conscientious about asking. It is a risk, I'll grant."