Unlike California, the East Coast does not have many Japanese restaunts outside major cities.
From my observation, most of New Jersey's restaurants are not friendly to young kids.
So, why don't start with in-store restaurants in Mitsuwa Supermarket? Unlike Los Angeles and San Francisco, New York does not have its Japantown.
About 15 years ago a "mini-Japantown" was set up, across the Hudson, in a New Jersey city--there was no "suitable" space in Manhattan.
I agree about Dai Kichi in Montclair. In addition to great food, the Sushi chef picks only the freshest fish several times a week, so the menu changes. They are very open to children and you might even be able to get a special seating time for educational purposes. I'm sure the chef would be happy to show your kids 'how it's done' also. Depending on how many students you're bringing, you might even be able to fit in the back room where you sit on the floor and remove your shoes in true Japanese style. Good luck. If you do go, post how it went.
I suggest Dai Kichi in Montclair, NJ.
We go there practically every Friday night - I suggest a reservation on the weekends. I've seen children there... Prices are comparable to any other Japanese place. They don't just serve sushi, either...
We've eaten Sushi in many different places all over the country, and this place is near the top, if not at the top of our list.
Also, if you'd like a great experience, extremely kid-friendly, try Mitsuma Marketplace in Edgewater, NJ. It's a huge Japanese supermarket, with an amazing food court, where you can order sushi, noodle soups, tempura, grilled & fried specialties. It's fabulous!
The url is below...
I can think of two places. The first place that comes to mind is KIKU on route 4 West (Paramus?). They have excellent sushi and it's a Japanese Steakhouse, great for the kids! The second place is called East Japanese it's on Teaneck Road in Teaneck. Also great sushi. They have other items also like tempura, soups, nagasaki? bbq (chicken, pork, beef, shrimp, veggies) on sticks.... You take off your shoes when you walk in and sit on the floor!