Born in 1513, Ito Yoshisuke was the 16th head of the Hyuga Ito clan. In 1568, after a roughly five-month siege, he seized Obi Castle from the Shimazu, making it the linchpin of a network of strongholds known as the "Forty-Eight Ito Castles." At his peak he controlled nearly the whole of Hyuga Province, presiding over the clan's golden age. However, after a crushing defeat by Shimazu Yoshihiro's forces at the Battle of Kizakibaru in 1572, his power rapidly collapsed. In 1577, driven out of Hyuga by Shimazu pressure, he fled to seek refuge with Otomo Sorin in Bungo. After Toyotomi Hideyoshi's pacification of Kyushu in 1587, his son Suketaka recovered the ancestral domain of Obi, but Yoshisuke himself had already died in exile in Sakai, Izumi Province, in 1585.

A cultured figure who loved waka and renga poetry, yet also displayed dogged persistence in the five-month siege that won him Obi Castle. His later years traced a dramatic arc of rapid decline before the Shimazu onslaught.

The network of the "Forty-Eight Ito Castles" and the conquest of Obi Castle that Yoshisuke achieved symbolize the peak of the Hyuga Ito clan. His downfall and his son Suketaka's later restoration to Obi are remembered in the castle town's history as a story of a Sengoku daimyo's rise and fall.