Not really in the parks other than Epcot. World Showcase has a sit down Japanese restaurant (lunch and dinner) with a good selection, and a counter service with limited menu (but a couple fun rolls). In Future World there is a food court in Land Pavilion that has some rolls, but nothing you would go out of your way to find. I am, pretty sure zero at MK. I have not seen any at Studios or Animal Kingdom.
Kimonos at the Swan is excellent -- dinner starts at 5:30, kareoke starts at 9-9:30 (it can be loud). You can take a look at it on swandolphin website.
There is a night time sushi stand at the Poly and California Grill has good (although limited selection) sushi creations as part of dinner menu.