We shop at grocery stores. In Meguro I use Sanwa, Ozeki, and Tokyu. When I lived in Daimon and Roppongi I shopped more at Hanamasa, Pororoca, etc. Convenience stores are for last minute top up stuff when the grocery store is closed. Most people do not shop at the expensive places like Seijo Ishii but as a periodic treat we do. That is for a different crowd. And when I am feeling flush I go to National Azabu. Not a fan of Meiji-ya. The new neighborhood Maruetsu Petit are actually very well stocked and not too pricey.