Takeda Shingen decides, at the height of the anti-Nobunaga alliance, to rise against the Oda clan.
Nobunaga, his forces tied down in siege warfare at Ishiyama Hongan-ji and Nagashima, sends insufficient aid to Tokugawa.
As Takeda Shingen drives south, seeking to attack Tokugawa at his fortress at Hamamatsu, his forces meet Tokugawa's on a high plain called Mikata, just north of the fortress.
According to the Kōyō Gunkan, the contemporary Takeda military history, Takeda outnumbers Ieyasu three-to-one, and organizes his men in the gyōrin (fish-scale) formation, enticing his opponent to attack.
Tokugawa's men are arranged in a line, so they can make the best use of their arquebusiers.
Tokugawa may have expected his superior weaponry to defeat the tactical attempts of Takeda, who now looses a cavalry charge, his mounted spearmen racing towards the gunners, and overrunning them; some of Tokugawa's men stand firm, but many withdraw or are killed.
A fresh set of horsemen initiates a new charge, led by Takeda Katsuyori and Obata Masamorim and are soon joined by the main body of the Takeda army, which drives their adversaries into full retreat.
Tokugawa seeks to re-engage the Takeda army, to free his trapped generals, but is persuaded by Natsume Yoshinobu to retreat; Tokugawa's life was too important.
Natsume is killed leading a charge into the Takeda line.
Tokugawa returns to the Hamamatsu fortress, reportedly accompanied by only five men, and commands that the fortress gates remain open, and that braziers be lit to guide his retreating army back to safety.
When the Takeda vanguard, led by Baba Nobuharu and Yamagata Masakage hears the drums sounding retreat, and see the braziers and open gates, they assume that Tokugawa is planning a trap; they stop and make camp for the night.
A small band of Tokugawa warriors attacks the Takeda camp in the night and forces the Takeda into a ravine, where they lie helpless.
Shingen and his army withdraw the following morning.