The Military Library is a repository of military knowledge located within the castle, serving as a critical resource for strategists and historians. It contains maps, records, and accounts related to various battles, including the notable Battle of the Snow Plain. The library is attached to the War College, highlighting its importance in training and educating military personnel.
Bayushi Monban sought maps and information about distances to the Snow Plain and Otosan Uchi, showcasing the library's role in providing logistical support for military planning. Monban's investigation revealed that the Castle of the Swift Sword is far from the Snow Plain, complicating missions within a short time frame. The library contains records from prominent generals, including Matsu Sakura and Matsu Matsu Morozane, whose accounts were analyzed for insights into the battle's failures. Kakita Kazumi and Shiba Midori utilized the library to confirm details of the Snow Plain peace treaty, examining the presence of witness chops and the timing of their application. The library facilitated their research into the historical context of the battle and the surrounding narratives, underscoring its significance as a center for military documentation and scholarly inquiry.