English: Koyo Gunkan (甲陽軍鑑) book cover (1656). It has the first mention of the term bushido. The scriptures are from Takeda-ryū (martial arts school), compiled by Kosaka Masanobu, and completed in 1632 by Obata Kagenori. It consists of 20 scrolls that mention Bushidō over 30 times. It contains the history of the Takeda family and their military tactics. The Koyo Gunkan describes valor and exploits in battle. For example it is a waste of talent when a Bushidō practitioner takes on administrative roles in government or financial affairs (e.g. dealings in rice, money, timber, or forest land), it emphasis that bushido lies only in "becoming as a spear" on the battlefield. Dr. Hiroko Willcock (senior lecturer at Griffith University, Australia) explained Koyo Gunkan is the earliest comprehensive extant work that provides a notion of Bushido as a samurai ethos and the value system of the samurai tradition.