This is Shikijo, a mask of the elderly with long white beard expressing wisdom. On the background, there are cranes which are said to live for 1000 years, to wish for longevity.
Noh is a form of Japanese theater involving music, dance, and drama originating in the 14th century, 200 years before Kabuki.
One key element of Noh are the masks which the actor wears. They tell the audience what kind of character is being portrayed. Frequently used masks represent demons and spirits, as well as women and men of various ages. The masks are carved from blocks of Japanese cypress. Their properties allows skilled actors to induce a variety of expressions with changes in head angles.