Hi Buttercup -
I used to live in Japan and have gone a couple of times back, but they have since added Disney Sea, and I haven't been to that park yet.
As for Tokyo Disney dining, I would definitely try "Queen of Hearts Banquet Hall" - it's in Fantasyland and it's so much FUN! It's a restaurant modeled after the Queen of Hearts in "Alice in Wonderland". It's self-service/seated dining, and if you have room for dessert, try their Unbirthday cake. It's a mini cake and it's actually pretty good.
A lot of the other good restaurants are on Main Street, if I remember correctly. I think East Side Cafe has an Afternoon Tea Set that is pretty cute, and I think I've eaten at their Plaza Restaurant, which was ok.
Not sure about disneysea dining, but I hear it's fabulous as well. A website that you might want to check out is
www.laughingplace.com - they have a Tokyo section. Have fun, let me know if you have other questions, you can PM me, or check out the other site. I AM SO JEALOUS - you're going to have such a good time!!!!!!