Taihei Oosako is an adult male character. He has black hair cut to ear length and gray eyes. His physique is muscular. He is commonly seen wearing practical attire: shorts and a tank top.

Oosako serves in the 108th Guard Squad, a military unit stationed in the Aomori region. This unit is under-equipped and holds low standing within the military hierarchy, functioning as a repository for pilots considered unsuitable for elite assignments. The 108th Guard Squad operates under persistent threat from enemy forces.