Sasamiya, Saya

Saya is Ayato's childhood friend, though they lost contact when Saya's family moved to Munich, Germany.

Saya's father is a meteoric engineering researcher, who designs and builds Luxes (mostly gun-type weapons) for Saya to use in battle. Her main objective behind entering Seidoukan Academy is to promote her father's weapons.

(Source: Gakusen Toshi Asterisk Wiki)