Saki Ootori is a mysterious young woman who confronted Mizuho on the school balcony. She grasped Mizuho and told her to be quiet, otherwise she wouldn't hear 'somebody's song'. At the very moment a girl, one of the students, fell down to her death. Saki acted as though she was fully aware of what was happening, implying that she might be the one behind the fallen girl's death. After that she called Mizuho by her name, much to the latter's surprise. Saki explained it by saying that there was nobody in this school who didn't know Mizuho's name because she was survivor of the tragedy. Then she proclaimed that the truth of the incident Mizuho's family was involved in was different from the one that everyone believed. Before leaving, she introduced herself and told Mizuho that they were the same.