Asahina Yasumochi served as a bushō during the late-Muromachi and Sengoku periods.  He was a retainer of the Imagawa clan.

In 1512, Yasumochi’s older brother, Asahina Yasuhiro, died and was succeeded by his lineal heir, Asahina Yasuyoshi, whereupon Yasumochi served as his guardian.

The Imagawa clan came into conflict with Shiba Yoshitatsu, the military governor of Tōtōmi, over control of the province.  In 1513, Yasumochi led the Asahina army on behalf of his nephew and participated in the action.  Yasumochi prevailed in the ensuing battle against the Shiba army including Ii Naohira and Ōkōchi Sadatsuna, the lord of Hikuma Castle.

Yasumochi died on 8/3 of Eishō 15 (1518).  He did not have an heir so this marked the end of his lineage.