Kōyō Gunkan

And the chronicle tells of the famous one-on-one skirmish fought by Takeda Shingen against Uesugi Kenshin at the fourth battle of Kawanakajima in 1561.

In one section, the chronicle gives a detailed breakdown of the entire Takeda army in 1573, counting everything from pages and banner bearers to kitchen staff, horse doctors, and finance commissioners.

The Heihō Okigusho, contained within the chronicle, and attributed to general Yamamoto Kansuke, is one of Japan's earliest treatises on martial arts, along with tactics and strategy.

It provides practical advice towards the wielding of sword, spear, gun and bow for the individual warrior rather than for the strategy of an entire troop.

He compares Shingen to the ideal lord, and contrasts him to his son Takeda Katsuyori, whose poor leadership quickly led to the downfall of the clan.