The Suruga-Sagami Conflict occurred in 1552 during the Sengoku Jidai era. Hojo clan daimyo Ujiyasu Hojo set his sights on Suruga Province as Yoshimoto Imagawa waged war elsewhere, conquering the region.
The warlords Ujiyasu Hojo, Yoshimoto Imagawa, Shingen Takeda, and Kenshin Uesugi vied for control of the Kanto region, fighting incessantly for decades. In 1552, Ujiyasu took advantage of Yoshimoto's preoccupation with other campaigns to attack Suruga, facing Yoshimoto's army. He defeated the Imagawa vanguard under Motonobu Okabe and Yasutomo Asahina, but, shortly after, the Uesugi army under Kenshin Uesugi and his sister Aya arrived. The two armies both sought to capture the central garrison, held by Tsunashige Hojo, and the Hojo defended the garrison from both the Takeda (led by Sakon Shima) and Uesugi armies. Kenshin Uesugi then attempted to attack the Hojo main camp, protected by Ujimasa Hojo, but Ujiyasu Hojo was able to defeat Kenshin and force his army to withdraw.
With the Uesugi army defeated, the Takeda moved to defend their main camp, with Yukimura Sanada heading to protect the Takeda camp. However, Ujiyasu Hojo intercepted his unit and defeated him. Ujiyasu proceeded to separately defeat the Takeda and Imagawa armies, and the two other warlords grew afraid of facing Ujiyasu in battle.