I’m a female member.

Universe doesn’t have an Obon holiday. (The back office is closed for Obon, but the staff handling arrangements are not.) I don’t think that’s Universe’s official account name for communication anymore. (That said, I’m no longer handling arrangements, so I could be mistaken. But since you haven’t received a reply, I feel like it probably isn’t the current account name.) As for LINE, I believe you registered two LINE accounts during your interview. Didn’t you receive information about the new communication LINE account through the other one? If so, you should be able to add the new LINE account from there. If you didn’t receive anything, and you’ve had even one date arranged through them in the past, you were probably given an emergency phone number at the time. You might want to call after 11:00 a.m. and ask. Another option would be to apply through the interview application page on their official website and explain what happened there.