Masakage was born in Shimotsuke Province in around 1500 to the Hitajima clan, a sub-servient clan of the Uesugi. Masakage was the brother of Masayuki Hitajima, and both of them fought in the Siege of Kawagoe Castle and the Battle of Teruyama. Masakage captured a Hojo steed, Ink Stone, and that became his mount. In 1548, three years after Kawagoe, he rode his horse into enemy lines during the Battle of Tochigi Castle, intending to either slay Hojo daimyo Ujiyasu Hojo or die a warrior's death. Toriyama Hojo, a second cousin of Ujiyasu, blocked the path and cut him down.