July 2nd, 1622
Tangible Cultural Property, designated by Sakata city
Donated by the Homma Family
This is a letter from Mogami Yoshiaki (1546-1614) to Kitadate Daigaku Toshinaga, Lord of Karikawa Castle. He orders him to quickly inform Shimura Izunokami Mitsuyasu and Shomji Uemon Hidezan of his arrival in what is now the town of Ōishida, and that he will be arriving at Kiyokawa (modern Kiyokawa, Shōnai Town) in three days time. In 1601, Yoshiaki, having again taken hold of Shōnai, which had been Uesugi territory, began to engage in the building of large-scale water works.
In 1611, Kitadate Daigaku became lord of the castle at Karikawa, and in in the same year he formally requested that Yoshiaki develop irrigation channels to divert water from the Tachiyazawa River (in modern Shōnai Town, Higashitagawa District) in order to deal with the problem of water shortages in the Shōnai plain. Construction began in March of the following year, and completed on July 21st.