Nerve wracking, serious and mildly challenging. But not impossible if you're prepared and don't get too nervous. I got the job but was put on the waiting list- mainly I suspect because I babbled too much which lost me a few points. (They use a point system)

Smooth. Interviewers were kind. Asked questions about why I wanted to join, asked me some questions in Japanese, asked about ways I could contribute as an ALT, and that was that.