to me transport costs will be the 1 that really kills big time . Not so much on food as there's a wide variety of choices that's reasonably priced & you don't need to eat very expensive food to survive in Japan
Family restaurants (such as Saizeriya) , combini stores (such as Lawson , Family Mart) do help a lot . You don't need to eat Kaiseki everyday to enjoy great food in Japan . Even I didn't ate over the top stuff when I went Tokyo last Dec
after I came back home , I will not demoan how expensive the transport cost in Singapore is now anymore especially since the government has subsided a huge chunk of it a great deal & yet Singaporeans still complain -_-
Wait until they go Japan to get shocked big time just how costly transportation's