Kosaka Masanobu

• Born: 1527
• Died: 1578
• Japanese: 高坂 昌信 (Kousaka Masanobu)
• Title: Danjô no Jô
• Other names: Gengorô, Toratsuna
• Son: Kosaka Masazumi
• Distinction: One of Takeda Shingen's 24 Generals

Masanobu, the son of a certain Kasuga Ôsumi no Kami, served Takeda Shingen first as a page, and then as a general, guarding the northernmost reaches of the Takeda domain at Kaizu castle. He played an important role during the Fourth Battle of Kawanakajima (1561) by leading a raid on the Uesugi positions at Saijô Mountain. Discovering that the Uesugi had already departed (to attack Shingen himself on the Hachiman Plain), Masanobu fought his way to attack Kenshin's army from behind and rescue his lord's faltering army. During the battle of Nagashino (1575) he was probing Uesugi Kenshin's defenses in northern Shinano and hastily marched south to protect Takeda Katsuyori's retreat when he learned of the latter's defeat. Nonetheless, he seems to have been generally ignored by Katsuyori and left to guard the fringes of Takeda territory. He died of illness in 1578 and none of his sons would survive the fall of the Takeda in 1582. He is attributed with at least part of the preparation of the Koyo Gunkan, a record of the events surrounding the Takeda since the rise of Shingen, although the bulk (if not all) of the text was probably written by Obata Kagenori years later.

References

• Initial text from Samurai-Archives.com FWSeal & CEWest, 2005