Kawachi

Kawachi in Shimotsuke included the country north of Utsunomiya, where the Kinu River terraces provided sites for medieval fortifications. Local tradition attributes Okamoto Castle to Okamoto Tomitaka during the Northern and Southern Courts period. Archaeology has identified parts of its main enclosure and outer moat dating to the fifteenth and sixteenth centuries. It served as an outlying stronghold of the Utsunomiya family and was abandoned after that family's dispossession in 1597.

Earthworks and the names of former castle-town quarters preserve traces of this military landscape. Under the Tokugawa, Shirasawa developed a different role nearby: it was the first post station on the Ōshū road after that road branched from the Nikkō road at Utsunomiya.