These documents, about 130,000 in total, were donated to the town by the late Okumura Takeo. They include the management records of the Okumura family, who were Ai masters/merchants, as well as material on the fertilizer industry, brewing industry, landowner management during the second decade of the Meiji era, and many other management history materials. It is also worth noting that a considerable number of local and historical documents of the feudal clan remain, as they were appointed as land tax collectors in the Tenpo era when they acquired Guntsuki Ronin status. In addition, an unprecedented amount of other historical material also remains, including political and educational material, along with more than 30,000 letters, etc.