The KOTANI family, which has existed since the Kamakura period, has a prestigious main building with a large entrance built in the Edo period in the Yamatomune style (gabled roof with thatched roof). In addition to this main building, there is a Nagayamon (gate building, and servants’ quarters) lined with several rice storehouses. The gate is a bajo-mon (carriage gate) which was transferred from the Karamete-mon gate of the HAKATA clan, which was the lord of the estate in the early Meiji period. It is one of the most representative village chief buildings in the Senshu area. In 1991, a foundation was established, and the building became a registered museum and opened to the public in 1994. The museum displays historical, folklore and art objects inherited from the KOTANI family, as well as archaeological objects such as ancient Japanese pottery.