Shiho Hahnenfuss wears a red ZAFT uniform, indicating that she is an ace pilot. Before joining the Joule Team she was a member of the ZAFT Ground Corps and, for a short while, the Le Creuset Team. While stationed at Boaz, she spent her time trying to improve the CGUE DEEP Arms's beam cannons, and later receives some help on this matter from Yzak, who has just returned from earth. During the Second Battle of Jachin Due, she fought against EA's female ace pilot "Sakura Burst" Rena Imelia but the fight did not have a conclusive end as she left halfway to destroy the nuclear missiles heading towards PLANT. After the war, Shiho returns to the research lab that she worked at before joining ZAFT. However this is brief and she soon rejoins ZAFT at the army's request, and briefly fought in the independence war of the U.S.S.A. After Yzak returns to the frontlines, Shiho rejoins the Joule squad and pilots a ZGMF-1000/M Blaze ZAKU Warrior. She seems to have romantic feelings towards Yzak but it is unknown if he feels the same way; if he does, however, he certainly does not make them known. Outwardly, Yzak considers her a loyal soldier and a trustworthy ally. Shiho chooses to wear the standard ZAFT uniform over the women's skirt-style uniform.
It has been remarked that Shiho was intended to be a tribute to Nami Tamaki, much like how Miguel Aiman and Heine Westenfluss are tributes to TM Revolution, however, Tamaki turned down the role, as a result, though Shiho often appears in crowd or background shots in the anime, and never has any dialogue. On another note, Tamaki's rejection may have been a blessing in disguise for Shiho, as celebrity voiced characters such as the aforementioned Heine and Miguel were quickly and brutally killed, leaving no more room for future development of the characters. It is now highly improbable that Shiho will ever be killed, as she has developed into one of the more popular minor SEED characters with her own following.