Lifespan: Meiō 6 (1497) to 8/30 of Kōji 3 (1557)
Title: Governor of Bitchū
Lord: Imagawa Ujichika → Imagawa Ujiteru → Imagawa Yoshimoto
Father: Asahina Yasuhiro
Siblings: Yasuyoshi, Toshinaga, Tomoaki
Wife: [Formal] Daughter of Nakamikado Nobuhide
Asahina Yasuyoshi was the son of Asahina Yasuhiro, a retainer of the Imagawa and lord of Kakegawa Castle in Tōtōmi Province. Following Yasuhiro’s death, Yasuyoshi became new lord of the castle. Owing to Yasuyoshi’s young age, his uncle, Asahina Yasumochi, served as his custodian.
Yasuyoshi served Imagawa Ujichika, Ujiteru, and finally, Yoshimoto, as a veteran retainer of the Imagawa clan. In the Imagawa kana mokuroku, published in 1526, Yasuyoshi is identified as a senior retainer on a par with Miura Ujimitsu. In other official communications of the Imagawa, Yasuyoshi’s name appears with Taigen Sessai. By marrying the daughter of Nakamikado Nobuhide, the older brother of Jukeini, Yasuyoshi became a relative to the Imagawa family.
Based at the stronghold of Kakegawa Castle in Tōtōmi Province, Imagawa Yoshimoto regularly relied upon Yasuyoshi for help with his military strategy for Tōtōmi and Mikawa. In this regard, Yoshimoto entrusted Utsuyama Castle on the western shore of Lake Hamana to Asahina Yasunaga and his son, Mototomo. Yasunaga was a younger cousin of Yasuyoshi. In 1548, Yasunaga and Mototomo provided support as lieutenant commanders to Taigen Sessai, the lead commander, at the Second Battle of Azukizaka.
In this battle, the Imagawa initially held the advantage owing to their hilltop position, but Oda Nobuhiro responded by having his men converge with the primary battalion under Oda Nobuhide. The combined forces overpowered the Matsudaira, and the will of the Imagawa wavered until a successful ambush turned the tide against the Oda. This led to disarray and caused the Oda to flee in defeat across the Yahagi River to Anjō Castle.
In 1549, Yasuyoshi was tasked with seizing Okazaki Castle after the demise of its young lord, Matsudaira Hirotada, at the age of twenty-four.
Yasuyoshi died of illness in 1557. After Taigen Sessai, Yasuyoshi ranked as the second highest lieutenant to Yoshimoto, so his death amounted to a painful loss for Yoshimoto. Yoshimoto himself was killed three years henceforth by Oda forces in a surprise attack at the Battle of Okehazama.