Food can cost you about USD$5-8 a meal if you eat at budget Japanese restaurants like Yoshinoya, Sukiya, and CoCo Ichiban Curry House. There are numerous bakeries around the country and a small snack will cost you around USD$1-2. The convenience stores all over Japan are also a quick cheap alternative and prices are extremely low compared with places back home.
I would say about USD$70-80 a day is possible done on a budget.
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