This is a water container which was formed into a cylinder at a potter's wheel, then transformed into a triangle and forcefully pressed down around the center of one side. A gray glaze was applied to reddish-brown clay with grains of sand mixed in, brush marks were boldly applied, and then lines were freely carved with a spatula as ornamentation. For Rakuzan ware, Matsudaira Tsunataka, the second-generation feudal lord of the Matsue Domain, made a request of the feudal lord Môri, and in 1677, Hagi potters such as Kurasaki Gonbei Shigeyoshi and others were summoned, and a pottery kiln was opened. At first Goryeo-style Hagi ware was produced, but in time, leveraging the iron-rich and pliant quality of Rakuzan's clay, Irabo, Totoya, and Hakeme bowls were fired.