Although it's somewhat less complex, similar vending machines that make poutine (a French-Canadian dish that's basically fries with gravy and cheese curds) have been around for a while in Montreal.
In thee machines, it starts with pre-cut fries. You see them dumped into some oil, fried for a bit, then dumped into the container. Cheese curds are then dropped on the pile, and it's finally shot with a bunch of gravy. All-in, it takes about four minutes, and it's pretty good poutine (if you like that stuff).
That would work well in Japan... There's already the restaurants/fast food where you choose the food on a vending machine get a ticket and give it to the kitchen staff... That would be a natural evolution of that...
Next thing you know, they'll be able to miniaturize and "cheaperize" still further and anyone will be able to buy one for home use. And they'll sell bags of all the ingredients you need.
Er... they've already done this, it's called microwavable pizza. You take the bag of ingredients (AKA frozen pizza) and insert said ingredients into the miniaturized oven and cook for 3-5 minutes.
Yeah, never try cooking a rising-crust frozen pizza in a microwave... really doesn't work. However, I bet these machines would reap a fortune in college dorms as an alternative to frozen crap.
In thee machines, it starts with pre-cut fries. You see them dumped into some oil, fried for a bit, then dumped into the container. Cheese curds are then dropped on the pile, and it's finally shot with a bunch of gravy. All-in, it takes about four minutes, and it's pretty good poutine (if you like that stuff).