Although this Japanese junior high school video is a bit long, it is one of the few out there that shows how the ALT interacts with the Japanese staff at the school and shows the under-belly (a bit at least) of how things really go in a school setting. Its 18 minutes and 16 seconds long. If you can't spare the time, the highlights are listed right below the video. The students shown in this video are in the first grade of junior high school. The location is in Ehime Prefecture in the town of Ikata.
Typical morning staff meetings are shown. And the general level of mild bureaucracy that is the hall mark of education in Japan.
Planning lessons as an ALT with the head teacher who of course is Japanese and executing them in the actual classroom setting.
Seiso jikan - or cleaning up the classroom after lunch on your hands and knees wiping the floor. Although I believe it to be a bit odd that the assistant language teacher is also on his hands and knees wiping the floor with a cleaning rag. (Especially considering there are about 40 fourteen year olds in the room available to do the actual cleaning.)
As well as how gym class goes. Mixed up with gymnastics and Kendo practice.
The video is quite balanced as this more serious side is mixed up with a decent helping of humor of having drinks after the day is done and a showing of your typical social life one might have in such a job. Drinking with fellow ALT's after the daily grind is over and chumming around about the antics that these young students pull.
It should give you a pretty good and clear image of what it would actually be like to be an ALT in Japan or at the very least give you a bit of a heads up on what to expect.