[1] Minowa Castle is located on a 30-meter high hill at the end of long ridge which extends from Mount Haruna southwest towards former Misato town in the northwestern part of Takasaki.

The castle, protected on one side by a deep valley created by the Shirakawa River and on its long, narrow hill, commanded both strategic roads.

By the Muromachi period, the Nagano clan were minor warlords controlling western Kōzuke Province and built Minowa castle as their residence in 1512.

In 1545, Uesugi Norimasa, the Kantō Kanrei and nominal overlord of the Nagano clan, was severely defeated by the forces of Hōjō Ujiyasu at the 1546 Battle of Kawagoe.

Finally, in 1566, during the Siege of Minowa by 20,000 Takeda soldiers[3] a sortie out of the castle was led by Kamiizumi Nobutsuna, this, however, resulted in a successful counter assault by the Shingen forces.

Takeda Shingen used Minowa Castle has his regional headquarters in Kōzuke, and at various times appointed generals such as Sanada Yukitaka and Naitō Masatoyo as castellans.

On hearing of Nobunaga's death, the Hōjō clan immediately seized Minowa Castle, recognizing its strategic importance.