Airi Arcadia is the younger sister of Lux Arcadia.
She has silver hair and ash grey eyes from being part of the Imperial Family. She is shown wearing the standard academy uniform. She wears a black collar as a sign of amnesty from the New Kingdom of Atismata.
She is mostly calm and care about her brother. In the Light Novel she is shown to care toward her brother and somewhat act like a mother to her brother. In both manga and light novel, she is calm when the Abyss attack the arena.
She was born as the daughter of the Arcadia Emperor and one of his wives. She was very sickly as she grew up.