Nezu Museum
Located in a prime location in Aoyama, a sophisticated area of Tokyo, it is one of the few private museums in Japan with a history dating back to before World War II. The museum has a collection of approximately 7,600 Japanese and Oriental antiquities (as of the end of December 2021), including 7 National Treasures, 88 Important Cultural Properties, and 94 Important Art Objects.
I highly recommend relaxing at the café in the Japanese garden after your visit. It's a great spot to soak in the artistic atmosphere.