Hitachi Province
The villages of Nagasao, Genseida, and Mamaita were created within Kawachi District, Ibaraki Prefecture the establishment of the modern municipalities system on April 1, 1889. At the same time, the village of Kanaetsu from Katori District, Chiba and a portion of Toyosumi Village in Shimohabu District, Chiba were transferred to Ibaraki Prefecture. The border between ancient Hitachi Province and Shimōsa Province was the Tone River; however, due to shifting of the riverbed by the Meiji period, it was located on the north bank of the river. The three villages originally from Hitachi Province were merged to form the village of Kawachi on April 1, 1955. On February 15, 1958, the neighboring village of Kanaetsu was annexed to Kawachi.