The Battle of Nagashino was a pivotal confrontation during the Sengoku period of Japan, involving two of the most powerful daimyōs, Oda Nobunaga and Tokugawa Ieyasu, against the formidable Takeda clan led by Takeda Katsuyori. The battle took place near Nagashino Castle, where Nobunaga's forces cleverly utilized their newly acquired firearms to counter the traditional cavalry tactics of the Takeda. The preparation that went into this battle was extensive, with Nobunaga orchestrating a strategy that took advantage of the terrain and his forces' superior firepower.

The Takeda clan, known for their cavalry prowess and military innovations, faced an army that had evolved in response to the changing nature of warfare in Japan. When the battle commenced, the Oda and Tokugawa forces established a series of defensive positions, using wooden palisades to shield their infantry armed with arquebuses from Takeda's fast-moving cavalry. As the Takeda army charged, they were met with a steady volley of gunfire, effectively breaking their ranks and inflicting significant casualties.

The victory at Nagashino marked a turning point in the Sengoku period, contributing to the decline of the Takeda clan and the rise of Oda Nobunaga as a major unifier of Japan. This battle also illustrated the transformative power of firearms in warfare, which would continue to reshape military strategies in Japan and beyond, laying groundwork for the future unification efforts in the country.