Fuminori Sakisaka is a young medical student whose life changes when he is involved in a car accident along with his parents, killing them and wounding him. He wakes from a coma with an exaggerated form of agnosia that causes him to see the world as covered in gore and people as hideous monsters. As he contemplates suicide in the hospital, he meets Saya, who he sees as a beautiful young girl, however, in reality, she is a horrific extraterrestrial monster whose appearance drives people mad. Due to their circumstances, the two become close and move in together, becoming lovers and incredibly dependent on one another.