The members of old-established Tomizawa family successively served as the head of the local village. While the family was conducting transport and financial businesses, women were raising silkworms in this house.
Built around the end of the 18th century, the house has a special sericulture room on the second floor and is one of the oldest sericulture houses in Japan. The house is big with 23.9m frontage and 12.9m in depth. It is characterized by its kaya (grass)-thatched roof with the front cut down to let light and air in the room.