月代 零

A second-year student at the academy. The younger sister of the main character, Ichito. She calls Ichito "Nii-nii." Her silver hair is symbolic of the moon. She has a fragile air about her. She is generally reserved, but when the time comes, she can speak mercilessly with a cold expression. She is sickly. During her first year at the academy, she would attend school on and off depending on her health. Now in her second year, she is able to attend school normally, but she still needs to go to the hospital. Rei is the sister of the King of Ryukyu, and as a Ryukyu priestess, she supports her brother Ichito with religious ceremonies. However, she sometimes blames herself for not being able to fulfill her role properly due to her poor health.