Lifespan: Bunmei 2 (1470) (?) to Tenbun 12 (1543) (?)
Other Names: Masayori
Title: Junior Assistant Minister of the Sovereign’s Household, Assistant Captain of the Imperial Guards of the Left Division
Father: Yūki Masatomo
Mother: Daughter of Komine Naochika
Siblings: Akiyori, Nasu Sukenaga, Gorō
Wife: [Formal] Daughter of Tamura Naoaki
Children: Yoshitsuna, Komine Yoshichika (?), Komine Yoshina, Kashiwagi Yoshitake
Yūki Akiyori served as a bushō during the Sengoku period. He was the eighth head of the Shirakawa-Yūki clan. The Shirakawa-Yūki were an illegitimate branch of the Shimōsa-Yūki clan governing the Shirakawa area in the southern portion of Mutsu Province during the Sengoku period.
Akiyori was born as the lineal heir of Yūki Masatomo, the seventh head of the Shirakawa-Yūki clan. In 1495, he was invested with the title of Assistant Captain of the Imperial Guards of the Left Division.
His father, Masatomo, wed a dowager from the Ashina clan and cherished a son born thereby named Gorō. Even after becoming advanced in age, Masatomo did not endeavor to transfer the headship of the clan to Akiyori. After maturing, Akiyori felt insecure of his position so, in 1510, with the assistance of Komine Naotsune and members of the Iwaki clan, he banished Gorō and succeeded to the headship of the clan. This conflict, however, weakened the Shirakawa-Yūki clan, resulting in the loss of a significant amount of territory.
Beginning in 1509, during an internal conflict in the family of the Koga kubō known as the Eishō Conflict, Akiyori aligned with Ashikaga Masauji. Later, his younger brother, Sukenaga, who became the adopted head of the Nasu clan, took his own life in an internal disturbance. In pursuit of revenge, in 1520, Akiyori solicited members of the Iwaki clan to invade Shimotsuke Province and battle against Nasu Sukefusa and Nasu Masasuke (father and son) but lost in the Battle of 縄釣し台 and retreated. In 1521, Akiyori joined an operation led by the Iwaki clan, with reinforcements demanded from the Utsunomiya and Oda clans, to topple Yamada Castle held by the Nasu clan. The combined forces then attacked Sukefusa at Kamikawai Castle but after each side incurred significant losses, entered into a settlement brokered by the Satake clan in the condition that Iwaki Tsunetaka wed the daughter of Nasu Masasuke.
In 1531, Akiyori revitalized the Nagakumosan-Chitoku Temple established by Yūki Munehiro, the founder of the Shirakawa-Yūki clan.
Under a recent view, Yūki Yoshitsuna was not the natural son of Akiyori but originated from the Komine clan and the Komine clan usurped the Shirakawa-Yūki during the Eishō era (1504 to 1521) instead of as is commonly understood during the Tenshō Incident. Consequently, Masatomo was succeeded not by Akiyori but by Shichirō (Yoshitsuna) from the Komine clan. As a result, Masatomo and Akiyori (father and son) were expelled by Komine Tomonobu and, for a period of twenty-five years, Akiyori lived as a rōnin, or wandering samurai, in Aizu. Finally, in 1535, through the offices of the Ashina and Shirakawa-Yūki clans, he returned to Shirakawa. If this theory is valid, then the references to Akiyori engaged in conflict with the Nasu clan would in fact be in reference to Yoshitsuna.