No one should have to really budget in Japan if they know how to make money. But if I had to, and I’ve done this before, I can survive off of 3000 yen a week, which is roughly equivalent to $40.00 U.S., on just yakitori from the convenience store and little snack foods I can add to rice.
I get a 5kg bag of rice and steam a cup full, which in turn lasts me for about a day or two. Leftovers I store in the fridge. You can buy 100 yen spicy chicken breast from any convenience store chain and add it along with some other additional seasonings.
Another favorite is pasta. Just boil up some pasta and instead of using tomato sauce, use two pinches of salt and a squeeze of lemon. This gives the pasta a light and refreshing taste that can fill you up.
My number one favorite though is Jiro Ramen of Kannai which is loaded with garlic. Fills me up every time and at a very good price. The golden rule here is quality and quantity combined while not trying to break the bank here.