Bi Hei hails from Jouto Village, raised alongside Shin and Hyou. As teens, he and his younger brother Bi Tou challenged Shin but were swiftly defeated, forging an enduring friendship within the group. He bears distinctive buck teeth, a goatee, dark brown eyes, and short dark brown hair, traits inherited from his father. He is married to Tou Bi. Initially marked by deep cowardice and anxiety, he masked his fears in early battles with exaggerated tales and lies. Serving under Taku Kei alongside Shin and Bi Tou during the Keiyou Campaign, his first combat at Dakan Plains plunged him into terror. Overcoming paralysis to save Bi Tou from an enemy soldier marked his first step toward courage, though the battle also claimed his brother's life, a loss that haunted him. Despite overwhelming fear, he fought through major conflicts like the Battle of Bayou and subsequent campaigns. Evolving from a raw conscript to a seasoned veteran in the Hi Shin Unit, Bi Hei rose through the ranks, advancing from foot soldier to 100-Man Commander and later 300-Man Commander, leading his own unit. His loyalty to Shin and the unit remained unwavering, though he openly questioned Shin's capabilities, speculating Kyou Kai might be stronger. His relationship with Shin blended deep camaraderie with frequent exasperation at Shin's ambitions. In recent events, he intervened to defuse tensions between the Hi Shin Unit and Kan Ki's forces after atrocities by Kan Ki's soldiers, an action that resulted in grave personal cost. His journey across numerous conflicts traces a gradual shift from a cowardly soldier to a reluctantly courageous and fiercely loyal figure, though core elements of his anxious nature endure.