I love 'Kaldi'
Kaldi coffee shop is probably my favourite shop in Tokyo. It sells coffee, obviously, and you're always given a free hot sample as you walk into their store but the reason I love it is they also sell international food.
I can indulge in cheap olives, couscous, pitta bread, chocolate covered pretzels, good dried mangoes and so much more....
Did I mention it's also very cheap?