Originally Posted by
valdor
For prepared meals Isetan is pretty good, at least the one in Shinjuku is. Train stations also have decent selections of ready meals. If you want ingredients, you can look up the nearest Aeon or similar.
Isetan is nice for the occasional pick up but way too expensive compared to what you'd find in your neighbourhood supermarket as far as prepared meals go. Sure you will have more variety and arguably better (slightly!) quality, but really, if you doing this regularly, it will really add up the Yen quickly~!