Isuzu Ichinose, older brother of Subaru Ichinose, enlisted in the Earth Federation Army at a young age. His exceptional skill propelled him rapidly through the ranks, yet he ultimately retired due to irreconcilable differences between his personal principles and military doctrine. After departing the Earth Federation, Isuzu aligned with the space colonization organization "People of Metus"—also known as "Citizens of Metus"—which opposes the Earth Federation. Within this faction, he holds an executive position and the rank of colonel, piloting a mecha in combat against Earth Federation forces.

This allegiance places him in direct conflict with his brother Subaru, a pilot for the Earth Federation’s Space Battleship Tiramisu. Isuzu possesses dark blonde hair, cyan eyes, stands 180 cm tall, and weighs 62 kg. Born on June 19th in Japan’s Aichi Prefecture, he has blood type B.

A temporary defection occurs when Subaru joins Isuzu’s faction seeking brotherly connection. During this alliance, the People of Metus deploy advanced technologies to enhance New Type pilots like Subaru. However, Subaru’s defection proves short-lived; he returns to the Tiramisu after a minor conflict, severing their brief partnership and reinforcing the ideological rift between them. The precise circumstances of Isuzu joining the enemy faction and the brothers’ familial history remain undisclosed.