Although Takeda Shingen is most often thought of as a military commander who led his troops into battle, in his everyday life he resided at the Takeda residence in Kōfu, where he administered the affairs of government in his domain. In addition to being the leader of a large number of vassals, Shingen’s major role was to protect the livelihoods of his subjects as the feudal lord of the land.

Surrounded by high mountains, the Kōfu Basin had only a limited amount of arable land suitable for rice cultivation, and even this land was often inundated by flood waters. Therefore, a flood control project was undertaken by Shingen to prevent rivers from overflowing by building a levee near the confluence of the Kamanashi River, which flows southward through the western part of the Kōfu Basin, and its tributary, the Midai River. This is the dike on the Kamanashi River that remains to this day, and is known as the “Shingenzutsumi” (Shingen Dike).

Despite the relative success of these flood controls, the fact still remained that there was limited agricultural land available for rice cultivation and trade was hampered by the province’s lack of a vital sea port. However, the mountains and forests produced high-quality timber, and the province was also blessed with gold mines. Gold is said to have underpinned Shingen’s military power, and there were two large, high-quality gold mines in Kai Province (modern-day Yamanashi Prefecture), Yunooku and Kurokawa. There is no doubt that gold from the Kurokawa mine was brought to the castle town of Kōfu for processing as the presence of gold from the Kurokawa mine has been detected in earthenware smelting trays excavated there. Kai gold was of high purity, and it appears that it could be refined relatively easily, so it was intensively produced by people known as “Kanayamashu” who lived off mountain resources during Shingen’s reign. Furthermore, Japan’s first gold coins, Kōshū gold, were minted at this time. The Takeda clan offered this gold to court nobles, shrines, and temples, and also rewarded their vassals with it. In addition, as rice was difficult to cultivate in Kai Province, the Takeda clan allowed for one-third of annual tribute to be paid in the local currency. This arrangement, which was unique to Kai Province, resulted in the development of a cash economy and the need for standardized methods of measurement with scales and masu, rice measuring boxes. Later, these practices were widely adopted throughout Edo Japan.

Furthermore, Shingen passed 57 laws for governing his domain in 1547, consisting of 55 articles to which two were later added, and these laws are known as the “Kōshū Hatto no Shidai” (The Laws of Kōshū).

The content of the laws was wide-ranging, but most of them related to land ownership and taxes, while others stipulated matters related to the master-servant relationship of warriors, the settlement of violent disputes, restrictions on exchanging documents with other provinces, and even the prohibition of religious disputes. It was very unusual at the time for a violation of the law to be litigated without regard to a person’s status, yet, even Shingen was subject to these laws.