[1][2] The battles were triggered after Shingen conquered Shinano, expelling Ogasawara Nagatoki and Murakami Yoshikiyo, who subsequently turned to Kenshin for help.

After the Ōnin War (1467–77), the Muromachi shōgun's system and taxation had increasingly less control outside the province of the capital in Kyoto, and powerful lords (daimyōs) began to assert themselves.

[7] Twelve days after taking Katsurao Castle, Shingen penetrated far into the Kawanakajima plain along the eastern bank of the Chikumagawa River.

Uesugi Kenshin marched up the western bank to support Murakami Yoshikiyo, and the two armies encountered each other at a shrine of Hachiman (place within modern Yashiro) on June 3, 1553.

Shingen pursued Yoshikyo across the Chikumagawa River but was turned back by Kenshin's reinforcements at the Battle of Fuse.

However, the Kurita clan, allies of the Takeda, held Asahiyama fortress a few kilometers to the west; they menaced the Uesugi right flank.

[14] After besieging Hōjō Ujiyasu's Odawara castle, Uesugi Kenshin was forced to withdraw after hearing rumors about the movement of Takeda Shingen's army.

However, the general in command of the castle, Kosaka Masanobu, through a system of signal fires, informed his lord, in Tsutsujigasaki fortress, 130 km away in Kōfu, of Kenshin's move.

However, whether via spies in Kaizu or scouts looking down from Saijoyama, Kenshin guessed Shingen's intentions and led his own men down to the plain.

Instead of fleeing Kosaka's dawn attack, Uesugi Kenshin's army crept down the mountain, quietly using bits of cloth to deaden the noise of their horses' hooves.

With the beginning of dawn, Shingen's men were surprised to find Kenshin's army ready to charge at them—as opposed to fleeing from the mountain, as expected.

[17] Uesugi's forces attacked in waves, in a kuruma gakari formation, in which every unit is replaced by another as it becomes weary or destroyed.

Seeing that his pincer plan had failed, Yamamoto Kansuke charged into the enemy ranks, being killed in action with his two chief retainers, Osaragi Shōzaemon and Isahaya Sagorō.

[17] Eventually the Uesugi forces reached the Takeda command post, and one of the most famous single combats in Japanese history ensued.

The chronicles seem to indicate that the Takeda made no effort to stop the Uesugi from retreating after the battle, burning the encampment at Saijoyama, returning to Zenkō-ji and then to Echigo Province.