Abigail S.
Yelp
This is an excellent museum that you can enjoy without the typical crowds, even on weekends. I believe that the director is also the head of the Muji retail brand, so the displays not only focus on more high art pieces, but also more utilitarian items like brooms, glass wear, pottery, and sweet molds. The collection not only includes pieces from Japan, but also England, Africa, and the American Southwest. There are pretty parks and play areas for kids also located in this surrounding area. Very chilled out compared to crush of people in central Tokyo.
Easily reachable if you take the Keio line from Shibuya Station (free if you have the JR Rail Pass).