Minobu town 

According to ancient documents, the Monzai family lived in Yunooku since the Muromachi Period. According to some of the oldest preserved documents in Japan, more recently discovered documents and writings on monuments, Jyonoshin Sano died in the 7th year of the Tenmon Period. Around the 12th year of the Tenmon Period, Nuuemon was a local magistrate of Yunooku and barrier guard of the Anayama family. The family name was "Sano" until the Momoyama period, but then changed to "Monzai". In the Edo Period, the family was in control of the Yunooku Gold Mine (Nakayama and other mines) and acted as the head and barrier guard of forests until the last days of the Tokugawa Shogunate regime. Ancient documents written at the time the family served as head and barrier guard are carefully kept, and documents that show family lineage are all in good order, leading up to the present head of family, Masaru Nishimasa. The building is 14.67m long along its crossbeam and 9.19m wide. It was made using single-layer Irimoya style and has a thatched roof. Documents are not clear on when the building was constructed, but it is one of the most important pieces of work done in the Irimoya style. Main construction styles for housing buildings in Yamanashi at the time when the building was constructed, are the Kirizuma style, found along the Oume route going into the Kofu basin from outside of the prefecture, and the Irimoya style that can be found in the Fuji River area. Judging from the style and technique of the building, it was constructed as a hall style building and built in the middle of the Edo Period. Some remarkable things about the house is that it is large, its beams are marvels of order and neatness, and materials used to build it are thick and big. These techniques show that this house is old and has a long and honorable history. After that, some parts of the house were re-built and fixed. Grass was put in the east , a kitchen in the earth floor, a ceiling in the room, floor with tatami mats and an end-room. However the main part of the building is in good condition, and has been selected as an important cultural asset in 1964. A long time has passed since this Monzai Family House was built, and the building was old and decaying. In 1969, the house was dismantled and fixed. The present building was re-built according to documents.