Under the banner of the last story of the human world, it depicts the dilemma of mankind facing extinction due to the rampant spread of an unknown virus. At this time, only children under the age of 13 are not infected by the virus, and these children are imprisoned by vampires who emerge from the underground city and used as blood suppliers to feed livestock. The two protagonists, Yuichiro Hyakuya and Mikael Hyakuya, try to escape, but only the former...