Japanese printmaker Yozo Hamaguchi (1909-2000) was perhaps the most renowned mezzotint artist of the twentieth century. This small private museum exhibits sixty of his works, and has frequent shows devoted to the work of printmaker Keiko Minami, who was Hamaguchi's wife.
Hamaguchi spent much of his career working in Paris and then northern California, and he developed his own techniques for printing color mezzotints, which are explained and illustrated here. Many of Hamaguchi's custom-made tools are on display, along with a printing press he used, and you can watch a short film (in Japanese) that explains how mezzotints are produced.
The work of Keiko Minami (Hamaguchi's wife) is also well represented here, though mostly in temporary exhibitions. Minami's charming, often surreal fairy tale-inspired aquatints can be found in the collections at MoMa, the Tate Modern and other major contemporary art museums.
The museum shop sells postcards and books devoted to the work of the two artists, and there's a small cafe area at the front of the museum. (Note that the museum is closed for weeks at a time between exhibitions, so check their website to confirm that they're open.)