Lifespan: Tenbbun 13 (1544) to 9/4 of Genna 2 (1616)
Other Names: Gensuke (common), Higashi Hisaharu
Title: Governor of Hizen
Lord: Shimazu Yoshihiro
Father: Ijūin Hisatsugu
Mother: Daughter of Ijichi Shigesada
Ijūin Hisanobu served as a bushō from the Sengoku to early Edo periods. He was a retainer of the Shimazu clan of Satsuma Province.
In the eighth month of 1559, Hisanobu participated in his first experience in battle. Hisanobu served in many battles including the Battle of Yokogawa in 1562, and, in 1567, during an assault against Magoshi Castle in Ōsumi Province. In the aftermath of the Battle of Kizakibaru that occurred in 1572, upon orders of Shimazu Yoshihiro, he built a stone monument common during the Sengoku period that depicted six Kshitigarbha (bodhisattvas who look over children, travellers and the underworld) to mourn for those fallen soldiers from the Shimazu and Ijūin armies. Later that same year, Hisanobu served meritoriously during battle in Arahira in lower Ōsumi.
He further served, in 1578, at the Battle of Mimikawa and, in 1584, at the Battle of Okitanawate. Around 1583, Hisanobu became a chief retainer of Yoshihiro and he served as the lord of the manor for Yokogawa.
In 1592, Hisanobu acted in concert with Umekita Kunikane who opposed the governance of Toyotomi Hideyoshi and joined the Umekita Uprising. In 1599, during the Shōnai Rebellion, as the lord of the manor for Iino, he dispatched troops to suppress the rebel forces.