Saya is a genius, and her high level of intellect is her major contribution to the group, though it often causes her to be stubborn and arrogant. She usually stays out of combat, preferring to think of strategies to help the others fight. However, this changes when the group prepares to leave the police station. She is Rei and Takashi childhood friend 

She seem to be mean but she is help and care for her friend 

She is helping other about thing they ever saw 

She is best friend to Cheria the Summoner , Rias,