Synopsis
Fifty years after a catastrophic war pushed Japan to the brink of ruin, a centralized system called Sound Health Everlasting Long Life (SHELL) forms the foundation of a new society. Through advanced nanomachine research and medical care, citizens are guaranteed a life free from illness, but in return they must work nineteen hours each day. Additionally, when someone loses their connection to the SHELL system, an extremely uncommon occurrence known as "Human Lost" triggers the transformation of humans into monsters called "Lost," which must be eliminated to prevent society's total collapse. Yet in this world where fear of pain and death is absent, antisocial behavior is increasing. Factory worker Takeichi plans to besiege the Ministry of Interior to protest his inhumane living conditions and persuades his friend, the unknown painter Youzou Ooba, to join his cause. When their suicide mission inevitably fails, Takeichi's body is irreparably damaged and he mutates into a Lost, with Youzou quickly following. During the ensuing battle, dispatch team member Yoshiko Hiiragi uses her ability to detect the Lost and discovers that Youzou possesses a unique capacity to revert to human form. As the third person to survive after becoming a Lost unit, Youzou soon joins Yoshiko in investigating the recent surge of Human Lost phenomena that threaten the last chances civilization has to be reborn.