GS, our Marriage editor has a lot of knowledge about Japanese food.
What foods do they enjoy? Are there any allergies?
That being said, you could go to the Japanese food site and look for recipes that your girls would like and that they could participate in cooking. You could also have them go to various sites and choose some foods. Then, YOU sift through them and see what you think would be appropriate. I like having final say on what is being cooked. Kids often don't understand what is too hard.
Where would you be cooking? I have cooked with groups of middle and high school kids in classrooms using various woks, rice cookers, electric skillets, griddles, and microwaves. I do appreciate a full kitchen!
Here are a few recipes that I think my kids would have enjoyed. I have put my own descriptive name on them. The actual articles have different names. Hope this helps.
Teriyaki Beef or Chicken Rice Bowl Potsticker Recipe Sponge Cake with Whipped Cream 
