One of the Blade Children, she was adopted and raised with the hope that she would not suffer like others like her. However, once Sayoko's identity as one of the Blade Children emerged, she is mysteriously pushed off the roof of the school. She survives miraculously and later recovers but suffers from amnesia, though she is happy with her current life and continues to live hopefully. Unlike the other Blade Children, she does not possess the characteristic slit-pupils.
(Source: Wikipedia)