「恥の多い生涯を送ってきました」
昭和１１１年――医療革命により死を克服し、環境に配慮しない経済活動と１９時間労働政策の末、ＧＤＰ世界１位、年金支給額１億円を実現した無病長寿大国・日本、東京。
大気汚染と貧困の広がる環状１６号線外〝アウトサイド〟で薬物に溺れ怠惰な暮らしをおくる〝大庭葉藏〟は、ある日、暴走集団とともに特権階級が住まう環状７号線内〝インサイド〟へ突貫し、激しい闘争に巻き込まれる。そこで〝ロスト体〟と呼ばれる異形体に遭遇した葉藏は、不思議な力をもった女性〝柊美子〟に命を救われ、自分もまた人とは違う力をもつことを知る。
暴走集団に薬をばらまき、ロスト体を生み出していたのは、葉藏や美子と同じ力をもつ男〝堀木正雄〟。正雄はいう。進み過ぎた社会システムにすべての人間は「失格」した、と。
文明崩壊にむけ自らのために行動する堀木正雄、文明再生にむけ誰かのために行動する柊美子。平均寿命１２０歳を祝う人類初のイベント〝人間合格式〟を１００日後にひかえ、死への逃避を奪われ、人ならざる者となった大庭葉藏が、その果てに選択するものとは――
貴方は、人間合格か、人間失格か――
"Mine has been a life of much shame."
Tokyo, 2036 (Showa year 111): a revolution in medical treatment has conquered death...
By means of internal nanomachines and the "S.H.E.L.L." system whose network controls them, human beings suffer no diseases, require no treatment for injuries, and are guaranteed a 120-year lifespan, free from illness. Yet this consummate social system warps the Japanese nation in a host of ways: unresolved economic disparities, ethical decadence resulting from deathlessness, grave environmental pollution, and the “Human Lost” phenomenon, in which people themselves, disconnected from the S.H.E.L.L. network, become malformed.
Japan teeters wildly between two potential futures: civilization's restoration, or its destruction.
Atmospheric pollution suffuses "Route 16" in the Outside--the area outside the Route 16 beltway. Yozo Oba, who lives an idle, drug-saturated life, joins Masao Horiki, a mysterious man who associates with the drag-racing gangs, on an incursion Inside--the area within the Route 7 loop where the privileged class lives--only to be embroiled in a violent struggle. When he encounters a malformed sufferer of the Human Lost phenomenon, a "Lost," Yozo's life is saved by Yoshiko Hiiragi, a girl of mysterious abilities who belongs to the anti-Lost agency H.I.L.A.M., and he discovers that he himself also possesses extraordinary powers...
Degradation and death. Life and hope. Buffeted by fate, a man tears himself apart and cries out. Rage. Sorrow. Pathos. Consumed by despair and bitter tears, Yozo Oba is himself transformed into a demon.
A human lost... or a human who can find himself?
