Mukuchi na Bakemono wa Yoru ni Naku

Oogimi Tsumugi is completely ignored at school because his parents are murderers and he has not talked to anyone in school for months. Then one day, a transfer student, Konohata Maya starts a conversation with him, but there's something eerie about her. She understands why Tsumugi is being ignored, but she seems to be even more interested after learning about his situation. What does Maya want with him and more importantly, what is she?