When I walked through this little one-horse town and found my yeogwan, no one was at the information desk. I called the number on display and spoke with the ajeossi running the place. He told me he was away at some event but would be back around 5:30. In the meantime, since I was alone, I could just walk into Room 203 (not at the end of the hall for once!), settle in, then pay the W35,000 fee once the ajeossi was back.
Gonna do that now, actually.