Known as Kaizu Castle built by Takeda Shingen, this was the most critical stronghold during the Battles of Kawanakajima. During the Fourth Battle (1561), it served as the Takeda frontline base. Sanada Nobuyuki entered during the Edo period, and the Sanada governed for 10 generations. Sakuma Shozan, pioneer of opening Japan, was from this domain.

Matsushiro Castle, originally known as Kaizu Castle, was constructed in 1560 under the orders of Takeda Shingen, with Yamamoto Kansuke said to have designed its layout. Built as a flatland castle that skillfully incorporated the Chikuma River into its defenses, it served as a strategic stronghold fo…