When the world died As a half-blood

Shoyo, a first year at his school, spent his whole school life as a loner. Untill, he meets a girl named Suzuki Mamoru, who becomes his friend. His high school days were going okay but one day he notices a women walking in a weird style, who bites one of his teacher at school. Suddenly after some time the teacher also becomes a monster like that women. This is a story of the survival of some high school friends in this post-apocalyptic zombie filled world where humanity has ended.