Nisu (Rice Mortar)
Large wooden nisu (mortars) are used to thresh grain and pound flour. The mortars vary in size but are usually quite large, requiring the user to stand and use both hands to hold the pestle. Though the nisu can be used for rice threshing, millet is more common in Ainu cuisine, with three varieties grown: Japanese millet (piyap), proso (menku), and foxtail (munciro).