Until recently I didn't really make a whole lot of food at home here in Japan. I mostly ate out or bought take home (a bento is only 500yen). Normally I generally only cook when it's for someone else but now that I'm between jobs I've been trying to save money and one way is to make my own meals. And so, even though I've see these places around I never really paid attention but now I've finally had a reason to notice that if you need cheap groceries then you should find your nearest Niku no Hanamasa.
They basically seem almost like a restaurant supply store. Most things come in sizes that are generally larger than you would buy at a normal supermarket. But, for Japan, the prices are pretty good. For example 4 large boneless chicken breasts for like 399 yen (about $3.50 U.S.). I bought 3 packs (12 breasts), cut them up and wrapped each one in saran wrap and froze them. At any time I can pop one out and quickly make something yummy.
If you are a starving student or just want to save some money you can find your nearest store here.