Yango is a fourteen-year-old orphan, the sole survivor of a train accident during the Tessik bombings that killed his parents. The incident left him with prominent facial scars across one eye and forced him into life as a street orphan who steals to survive. He wears a short green cape, a red scarf gifted by his mother, a black shirt, beige baggy pants, and unique loincloth-style arm guards and shoes.

Implanted with a Hiruko entity to become a Xam'd, Yango struggles to control his transformative abilities. His emotional instability and abandonment issues make him vulnerable to the Hiruko's influence, risking permanent petrification or monstrous transformation if he activates his powers carelessly. He first met Nakiami while stealing an apple; after she witnessed him use his Xam'd arm to attack a pursuer, she bandaged the Hiruko eye on his arm and extracted his promise never to use his abilities impulsively, establishing a critical boundary for his survival.

Despite his distrustful and hot-blooded demeanor, Yango demonstrates compassion. He once assisted a Tessik villager oppressed by cargo restrictions by pretending to be the villager's brother to legally increase their carrying capacity. He views Nakiami as a parental figure, manifesting fierce protectiveness driven by fear of abandonment. He declared, "I'm supposed to protect her! We're meant to be together! She needs me!" This culminated in him forcibly restraining her in his Xam'd form to prevent her return to a besieged Tessik village, prioritizing his need for her presence over her safety.

Yango is the only known incomplete Xam'd in the series, his unresolved emotional and psychological struggles hindering full integration with the Hiruko. His development remains constrained by this instability.