Zen Seizaki, a public prosecutor at Tokyo District Public Prosecutors Office, is investigating a case of illegal clinical research related to a drug company and a university. During the investigation, he finds a file that Shin Inaba, an anesthesiologist, kept, which includes blood that is mixed with hair, skin, and a paper written with letter F. As he investigates, he realized there's a hidden plot that is connected with a huge election as well as to a certain person who is in charge of it.