Hideomi Iba, a 29-year-old covert operative within the Japanese Imperial Army’s Military Affairs Bureau, operates from the clandestine Kudan Satellite Office. Employing the alias "Tada," he masquerades as a *Monthly Real Crime* journalist to infiltrate entities like V Shipping Company and Alma Trading Company, probing their suspected foreign collusion and shadowy dealings. His reassignment from the Harbin Military Secret Service followed whispers of the Ministry of Home Affairs conspiring with an external group, prompting him to lead investigations into these alleged ties while coordinating discreetly with his team.

Known for analytical rigor, he challenges unverified theories—such as a speculated Hyakko Party connection to Kuratake’s jailbreak—demanding methodical evidence over conjecture. His intellect surfaces in precise recall, exemplified by reconstructing details from a briefly glimpsed map. A stickler for protocol, he enforces strict adherence to his civilian cover, forbidding military titles like "Major" during undercover operations.

Iba’s career reflects a strategic mind navigating military countermeasures against foreign threats, advocating decisive action amid bureaucratic friction. Tensions with superiors underscore jurisdictional clashes, particularly when foreign agents gain operational leeway on Japanese soil.

Physically, he presents with black hair trimmed at ear length, steel-gray eyes, and a composed demeanor befitting his age. His narrative remains anchored to the main series, with no expansions documented in supplementary media.