The only Escape ceremony location inside Epcot is in Canada. You could have a ceremony in Japan if you chose a Wishes wedding, but you wouldn't be able to have the reception in one of Japan's restaurantsit would have to be in a private event space somewhere.
If the restaurant is more important to you than the ceremony location, you could have an Escape ceremony somewhere, then change into street clothes and make a regular dining reservation at one of the restaurants in Japan. Just know that they can't guarantee large parties will be able to sit together (although I think that would be easier at Teppan Edo cuz of the big tables!).