The Alice Death Princess

Shirui is the daughter of Persona, Rei Serio. She had a mission to spy on Ruka for 2 years, the mission was given when she was 5. Shirui was then adopted by Ruka's parents after hearing she had none. She met Natsume when attending the same school and lived with Ruka. They were soon captured by the academy as Shirui wanted and she managed to meet her father again.

No one knew of their relationship as Father and Daughter except the ESP. She wore a snow fox mask to keep her identity and never spoke a word till necessary. She has fox like instincts to sense who had what alice. Knowing Kokoroyomi had Mind Reading as well. They spoke by Mind and got along well.