hehe good job!!

a small tip for saving more money (to use then for buying more goods!) during Magical Mirai: if you have breakfast option at hotel, and you can choose what to eat, try to eat something that makes you full during the day, so try to choose something like rice, sausages, a salad and a fruit juice.
Convenience stores are a very good option too for a nice meal, you can find fresh made meals (for example spaghetti or bento boxes):
https://www.sej.co.jp/products/a/pasta/
https://www.sej.co.jp/products/a/bento/
the convenience store cashier might ask you "obento atatame-masu ka?" which is asking for if you wish the meal to be warmed up in the microwave ("hai, onegai shimasu" yes please, or "iie, daijoubu desu", no thanks it's ok)
there are also hot snacks, you can buy to eat somewhere else, or even frozen food, like small pizza, most of them are ok to be cooked with a microwave (and usually every hotel has a microwave in the common area):
https://www.sej.co.jp/products/a/hotsnack/
https://www.sej.co.jp/products/a/onigiri/
https://www.sej.co.jp/products/a/bread/
and like I wrote before, it's important to bring a small backpack with some snacks and a couple of drink bottles. There are vending machines almost everywhere, but having a drink ready (especially if you're making a long line) it's always a good idea

and other places to eat well and at good prices are the family restaurants or some japanese chain restaurants. (especially after the evening concert, you'll feel very hungry) If you see a ticket vending machine at the entrance of some of those small restaurants, it means you can buy the "ticket food", most of them has english menu with pictures too, then enter and give those tickets food to the waiter/waitress, it's so convenient!
