Set in the early 21st century with the population decimated by bio terror. Two kinds of humans now exist. One is the Nokusu who were infected with a virus but survived, consequently they carry an antibody. Most are young, healthy and have high intelligence, but they have a high sensitivity to ultraviolet rays and are active mostly during the night. The other group are the Kyurio. They survived by never having the virus. Tetsuhiko Okudera is a Kyurio. He was born in a poor village. He isn‘t happy with being a Kyurio and wishes he could be a Nokusu. Yui Ikuta is Tetsuhiko‘s childhood friend. She tries to revive the poor village.
