Noge Ōtsuka Tumulus, located in Setagaya Ward, Tokyo, is an 82-meter long, scallop-shaped tumulus constructed around the 5th century during the mid-Kofun period.
The tumulus has four burial facilities, and a box-shaped stone coffin was excavated from the second burial facility in 1897. Today, the objects excavated at the time are in the collection of the Tokyo National Museum.
From the second burial facility, a wide variety of steatite models used as ritual objects were found along with weapons (iron swords and iron blades) and accessories (agate comma-shaped beads, jasper cylindrical beads, and glass beads). Among the steatite ritual objects are steatite tubs. These are models of a wooden tub, which were made smaller than the actual object, and were used during rituals. They each represent the central part of a water transmission facility for filtering water. The steatite clogs are models of wooden clogs. According to a theory, ritual performers at the time wore these steatite clogs in order to prevent the water, which had been purified using the water transmission facility with a tub, from getting contaminated. The steatite vessels and plates were modeled after earthenware or wooden utensils that contained food and drinks during rituals. Steatite models associated with such water-related rituals have rarely been found and therefore valuable.
Steatite models of agricultural tools have also been excavated. The steatite ax and sickle are modeled after iron blades of an ax and a sickle without the handle. The steatite knives are models of iron knives housed in leather sheaths. Iron sickles were mainly used as agricultural tools, while axes and knives were chiefly used as handicraft tools. Kofun-period chiefs may have had these steatite ritual objects made wishing for prosperity in agricultural and handicraft production. More than 232 steatite knives have been excavated from this tumulus, and it boasts the largest number of such objects unearthed from a single burial site in eastern Japan.