Sayaka Murakami, granddaughter of the renowned psychic Bokudoh Murakami, seeks help from molecular biology professors Komada and Koshigaya. Her grandfather vanished after detecting the demon virus within politician Masajuro Tabeh, prompting her request and drawing the professors into her crisis. A group of thugs connected to the city's demon virus infections pursues Sayaka, aiming to use her to locate Bokudoh. During the search, Sayaka finds herself drawn to Komada, who battles partial control over his own demon virus infection. Komada sacrifices his remaining humanity to save Sayaka from mortal peril during a violent attack. This sacrifice forces both to confront the impossibility of a relationship as Komada fully embraces his demonic nature to ensure her survival.