Ei Hisatora served as a bushō during the Sengoku and Azuchi-Momoyama periods.  He was a retainer of the Shimazu clan and served as the seventh head of the Ei clan.

The Ei clan were an illegitimate branch of the Kimotsuki family.  The clan was founded by the son of Kimotsuki Kanemoto (the eleventh head of the Kimotsuki clan) named Kanemasa who adopted the surname of Ei.

In 1558, Hisatora was born as the second son of Ei Kanekata.  In 1570, his older brother of a different mother, Ei Kaneari, was murdered, so Hisatora became the successor to the clan.  In 1576, Hisatora participated in an assault against Takaharu Castle and, two years later, in the Battle of Mimikawa.  In 1580, he joined the deployment to Minamata, and, by around this time, he served as the head of the villages of Ei and Ibusuki in Satsuma Province.

Around 1582, Hisatora deployed to Hizen Province and incurred injuries during an assault against Chijiwa Castle.  In 1584, he served in the Shimabara Campaign, and, in 1585, joined Yamada Arinobu to conduct reconnaissance in Hizen and elsewhere.  Hisatora received enthusiastic praise from Shimazu Yoshihiro.  In the fourth month of 1587, he served in the Battle of Nejirozaka but died later that year at the age of thirty.

Hisatora was succeeded by his son, Ei Hisabue.