The surrounding area is roughly in the geographic center of Etchū Province and is a wide plain with a number of large rivers.

As the Hatakeyama waned in power and influence in the 15th century, the two clans waged a constant war for dominance over Etchū, with the Ikkō-ikki helping play one side against the other.

The Uesugi plan placed Kojima Motoshige, a former retainer of the Jinbō, in charge of the castle as castellan, and he suppressed an attack by the Ikkō-ikki in 1571.

After Kenshin's death, Nobunaga extended his power into the region, placing Jinbō Nagatsumi back in charge of Toyama Castle in 1578.

Narimasa also began a series of flood control works which gradually transformed the area surrounding the castle from a marsh to rich rice lands.

After defeating Shibata Katsuie at the Battle of Shizugatake, Hideyoshi gradually extended his control over the Hokuriku region and placed his general Maeda Toshiie in Kaga Province.

Narimasa responded by fortifying his border with Kaga and by making a pre-emptive attack against the Maeda at Suemori Castle, but was defeated.