The application process starts in October the year before hiring, so this can't be a split decision. The application includes a 1 page essay in which you are to argue why you think you're a good fit for the program. If you are selected for an interview, these will be held in February. The main purpose of the interview seems to be to determine how flexible you are, since even the people hiring don't know exactly where you will end up in Japan, or what level of school you will teach at. If you have claimed some level of Japanese proficiency on the application, expect to be tested on it a little. If you pass the interview, you'll hear of it sometime in April.

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.