Akaza is a demon affiliated with the Twelve Kizuki, holding the position of Upper Rank Three. Over a century ago, Akaza was a human by the name of Hakuji, a prodigious martial artist who trained under Keizo while nursing his daughter, Koyuki, who would later become Akaza's fiancée. Akaza is a headstrong, stubborn, and battle-crazed social Darwinist who enjoyed fighting, especially against strong Demon Slayers. He purposefully drew out fights to savor every moment of it.