MUJI YURAKUCHO SHOP (無印良品 有楽町店)
THE BIG MUJI
It's probably the biggest Muji store I know. It just had gone thru the renovation and it looks better than ever. Having the usual Muji stuff as well as cafe and meal , Muji books. You can easily spend hours in the store.
There is also a LOFT just opened by Muji that you can spend another few hours. they have all kinds of creative crafts, unique toys, and households goods. It's fun!!