[steven]

If you're gonna be moving around a lot, it might be hard to have ingredients and stuff like that... I can't imagine lugging around pots & pans or spices & ingredients and junk.

Another option is to buy store-made food. A lot of stores make a lot of semi-decent food. It won't taste as good as a restaurant (sometimes it can though), but you can get some things for cheap. Stores near me have stuff like 5 croquetes (i don't really know how to spell that) for 100 yen. You can get rolls of sushi for like 200 yen that will fill you up (but are monotonous).

I just realized that there is something you might not know about Japan-- if you go to the stores at certain times (usually late... like after 7 or so) you can get really good deals on stuff. I've gotten like party platters of sushi/sashimi for 700 yen because they were half off.