I went to Chukyo University in Nagoya several years ago. I think I was in only the second group of ISEP participants to Chukyo, so they hadn't yet worked out all the kinks in the system, but at the time, that was just great for me! Here's what it was like:
You of course must take Japanese language classes. I actually didn't learn a lot in those classes, though. Looking back, I wish I would have taken the writing classes they offered, as they probably would have been more useful for me personally at the time. But I digress.
On top of the Japanese language classes, you had the entire spectrum of the course books to choose what other you wanted to be in. These classes were regular college classes that you took with the regular Japanese students doing the regular program. I took classes on law, Japanese literature, linguistics, etc. This is where I learned just a TREMENDOUS amount of Japanese, as you are expected to do the homework just as the regular student, even if your language skills aren't quite up to the task. The nice thing was that the teachers would account for your special circumstances and let you write a shorter report or sometimes (although this never happened to me) would allow you to write your report in English, rather than Japanese.
Those classes are what you make them to be. You can either take classes that are popular among the English speaking crowd and get a support group that way, or you can take classes where you are the only non-Japanese native speaker in the class. The plus to that is that you will learn A LOT, but the downside is that you will do it alone. You of course will make friends with your classmates, but...
For example, I had a class that was for graduating students about Genji Monogatari. In this class we had to read the original classical Japanese, break it down grammatically kana by kana, and then translate it into modern Japanese. I went into this class without ever having studied classical Japanese, and I was in way over my head. I studied my butt off, though, and when it came to my turn to do the next installment, I did it with my groupmates, but they would only help so much. The rest I had to make up with sweat and tears.
Even if you don't take the sink-or-swim approach that I did, you will learn a lot if you make friends, join a circle, and participate in class. The people there are extremely friendly, and I don't have a single bad thing to say.
There is a sizable foreign community, but they mostly come from China, Taiwan, or South Korea. They are very nice, too, but don't expect much English.
Those foreign students had to basically find their own room and board, but as a member of the ISEP program, I was put into a local apartment building near campus along with the other ISEP people. I believe there were about 6 of us at the time. It was a small but safe apartment complete with a person to greet you at the front door. Very nice.
Anything else you want to know?