Jō Anno commands the Hero Section at Earth Defense Force's Saitama Branch, directing operations against the alien Censor Bugs. He is Retto Enjō's uncle and personally recruited Retto into the HxEros team after a Censor Bug attack compromised Retto's childhood friend, Kirara Hoshino.

Scientifically, Anno engineered the specialized XERO gear technology, enabling HxEros members to weaponize their H-energy against the Censor Bugs. Early XERO models exhibited critical vulnerabilities: susceptibility to clothing destruction during energy discharge and dangerous H-energy accumulation during prolonged wear. His ongoing research focused on refining the suits to endure energy output and eliminate these operational hazards.

Anno's distinctive, feminine appearance consistently unsettles Retto. Organizationally, he serves dual roles as the Saitama HxEros team's technical support specialist, maintaining vital equipment, and their strategic supervisor. He also manages the practical logistics of their missions, including the replacement clothing budget necessitated by frequent collateral damage.