Lifespan: Kyōtoku 2 (1453) to 5/14 of Eishō 12 (1515)
Title: Secretary of Popular Affairs, Assistant Vice Minister of Popular Affairs
Clan: Kumagai (from the Kunika branch of the Kanmu-Taira clan)
Lord: Takeda Motonobu
Father: Kumagai Munenao
Kumagai Yoshinao served as a bushō during the late Muromachi period. He was the lord of the Aki-Kumagai clan. In 1453, Yoshinao was born as the second son of Kumagai Munenao. While serving as a retainer of the Aki-Takeda clan, he endeavored to unify the Kumagai clan in the wake of its fracture and increase their influence.
As a member of the Kumagai clan, he was known as a courageous warrior. In the ninth month of 1499, after Nukushina Kunichika separated from Takeda Motonobu, Yoshinao eliminated Kunichika, for which he received the former territory of the Nukushina clan as a reward.
At the time, the landholdings of the Kumagai clan were allocated among the family. As necessary, Yoshinao went to great efforts to create an organization of regional landholding families based on divided inheritance under the leadership of a main heir.
During the time that he led the clan, Yoshinao eliminated a cadet family known as the Shinjō-Kumagai family, consolidating the power of the Kumagai clan which had been divided as a means to prepare for the challenges ahead in the Sengoku period. Kumagai Naofusa and his eldest son, Kumagai Naoshige, from the Shinjō-Kumagai cadet family were pardoned and, after changing their surnames to Kirihara, served as retainers for the Kumagai.
In 1506, Yoshinao’s eldest son, Kumagai Motonao, received landholdings from his lord, Takeda Motoshige so, around this time, Yoshinao is surmised to have transferred the headship of the clan to Motonao.
On 5/14 of Eishō 12 (1515), Yoshinao died at Isegatsubo Castle. He was sixty-three years old. Just two years later, in 1517, his eldest son, Motonao, was killed in action and the relationship between the Kumagai clan and their lords, the Takeda, became unsettled.