Also called: Kousaka Danjou Masanobu (高坂弾正昌信), Kousaka Danjou Nosuke Masanobu (高坂弾正忠昌信), Kasuga Toratsuna (春日虎綱), Kasuga Gensuke (春日源助)
Title: Danjou Nosuke/Faithful True-Shot (弾正忠)
Kousaka was born in Kai to a wealthy farmer, Kasuga Ookuma (?) (春日大隈). His father died when he was 16, and he lost a lawsuit against his elder sister's husband for ownership of his father's lands. He then enrolled in the service of Takeda Shingen.
Kousaka first served as a messenger for Shingen. He distinguished himself in battle, and rose swiftly through the ranks of Shingen's trusted retainers. He participated in most of Shingen's battles. He did not hesitate to retreat when required, which earned him the nickname of "Escaping Danjou". However, he was calm and logical in the midst of battle, and was perhaps the best of Shingen's generals.
After Shingen's death in 1573, Kousaka continued on to serve Takeda Katsuyori. He sought an alliance between the Takeda clan and their old enemy, the Uesugi clan, in order to unite against the threat of Oda Nobunaga.
Kousaka died in 1578 of illness at the age of 52. He was succeeded by his second son, Kousaka Masamoto (高坂昌元), his first son, Kousaka Masazumi (高坂昌澄) having died in the Battle of Nagashino in 1575.
In Mirage of Blaze: A kanshousha who, along with Sanjou-no-Kata, breaks the barrier over Takeda Shingen's tomb, the Maenduka, in an attempt to resurrect Shingen by using Narita Yuzuru as a vessel for his spirit.
According to Haruie, Kousaka has a high level of spiritual sensing ability (reisa), such that he is able to recognize someone he had met before even after their soul has undergone purification. He warns Naoe that Narita Yuzuru's existence is a threat to the Roku Dou Sekai.