Though Eri Kiuchi (木内えり, Kiuchi Eri) was the quieter one, while Katsumi Sato (佐藤勝美, Satō Katsumi)was more extroverted and outspoken they were good friends and never quarreled. Behind her facade of confidence, however, Katsumi was always jealous of Eri because Eri's grades were slightly higher than her's, and she was always being compared to Eri. Seeing how there was only one available spot for a scholarship for the prestigious N high school that both were striving for, Katsumi knew that she would lose and thus found a curse in an old library book and placed the curse on her friend Eri, out of jealousy. Eri began hearing strange voices, saw illusions, and faced near death multiple times, thanks to the curse.