A mysterious virus suddenly spreads throughout Japan causing widespread panic. People infected with the virus are called ZQN. The ZQN attack people with superhuman strength and their victims also become ZQN. Hideo Suzuki happens to meet a female high school student, Hiromi Hayakari. They run away from the city together, but Hiromi has been already bitten by a baby ZQN. The baby ZQN that bit her did not have teeth and Hiromi is in half state of ZQN. They then meet Nurse Yabu at a shelter. Yabu hopes she can draw an antibody from Hiromi. Based on the manga series "I Am a Hero" by Hanazawa Kengo.