Thanks for your replies WDWDancer and swillis. I have the menus but I am just not sure when/how the sushi is included. In at least one of them it isn't under the appetizers or the entrees so I'm not sure if we can use it as either.
The Teppanyaki Restaurant is going to be closed when we are in WDW. The other Japanese restaurant doesn't take reservations so I'm sure it will have a long wait.
DD(20) had sushi at WPC and loved it. You have to get it as your main course on the DDP, but they'll bring the full sushi menu for you to order from so the selection is much more varied than just the sushi appetizers.