Rei doesn't find it above herself to reprimand Takashi for acting carelessly. She worries about his well-being whenever he goes to fight "them". Rei has also proven to be a skilled combatant through the use of sojutsu ("Spear Techniques") and is a strong asset to the group.
Initially in the same year as Saeko, Rei was held back despite being an excellent student. Her father - a police detective - had been investigating the corruption behind the father of Shido, one of the teachers at her school. As a result of this he held her back purposefully. Rei bears a lasting grudge against him and feels uneven whenever he's around.
After having escaped the high school and resting at the family mansion of Saya, she and the group are in search of their parents.
Voiced by: Marina Inoue (Japanese), Jessica Boone (English)