Tokyo convenient stores

My family and i will be in tokyo for almost 3 weeks where we have rented an apartment,what i would like to know is if there are any good and reasonable priced convenient stores we should bye our daily needs from since it will be good for us also to saved some money and not bye from expensive stores.

Convenient stores (stores that are convenient) or convenience stores (7-11, Lawson, etc.)?

If its the former then it would be helpful to know the location of your apartment. If its the latter then it would be cheaper (but less convenient) to shop at a local supermarket. Here's some more info on convenience stores:

http://www.japan-guide.com/e/e2071.html

The address of the apartment is :3-7-6 Yushima, Bunkyo-ku TOKYO : and sorry for the misunderstanding i mean convenience stores where daily needs are sold:)

And when i say stores i more or less mean supermarkets to shop at:)

There are combini at every turn. Check it out when you arrive.

There is a Hanamasa store about 3 minutes walk from where you will stay:

http://maps.google.com/maps?f=d&source=s_d&saddr=Unknown+road&daddr=Un...

There is another supermarket over by Okachimachi station:

http://maps.google.com/maps?f=d&source=s_d&saddr=Unknown+road&daddr=Un...

Two blocks east is the Matsuzakaya department store, although food here will be more expensive:

http://matsuzakaya.web.transer.com/bb_url_ej.php?ctw_=sT,eCR-JE,bF,hT,...,

The whole area around Okachimachi station has plenty of shops and stalls selling fresh fruit, vegetables and fish, along with drug stores, etc.