Human Lost

is a 1948 Japanese autobiographical novel by Osamu Dazai. It is considered Dazai's masterpiece and ranks as the second-best-selling novel in Japan, behind Natsume Sōseki's Kokoro. The book was adapted to a live-action film in 2009, the 100th anniversary of Dazai's birth, which was directed by Genjiro Arato, the producer responsible for the award-winning Zigeunerweisen in 1980. It was released on February 20, 2010 and was marketed outside Japan under the title Fallen Angel. A new version of the live-action film was released September 13, 2019, starring Shun Oguri in the role of writer Osamu Dazai.

The book was also published into variants of manga. The first by Usamaru Furuya for 3 volumes, serialized in Shinchosha's Comic Bunch magazine in 2009, followed by an English edition published by Vertical, Inc. in 2011–2012. The second by Yasunori Ninose titled serialized in Champion Red from April to July in 2010. The third version was commissioned for the Manga de Dokuha series (comic adaptations of classic literature), published by Gakken. An English edition was published for online format by JManga in 2011. In 2017, mangaka Junji Ito published another adaptation while retaining the original title.

The book was adapted into anime among trivia through Bungou Stray Dogs to the first 4 episodes of the Aoi Bungaku series which received the Platinum Grand Prize at the Future Film festival in Italy. A sci-fi 3DCG film titled Human Lost by Polygon Pictures premiered on October 22, 2019 on U.S theaters.

Plot
The original book is told in the form of notebooks left by one Ōba Yōzō (大庭葉蔵), a troubled man incapable of revealing his true self to others, and who, instead, maintains a facade of hollow jocularity. The work is made up of three chapters (memoranda), which chronicle the life of Ōba from his early childhood to his late twenties.

2017 manga
Yozo meets Osamu Dazai himself during an asylum recovery, thus giving him permission to tell his story in his next book. The manga includes a retelling of Dazai's suicide from Oba's perspective.

2019 anime film
"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. Youzou 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," Youzou'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, Youzou Oba is himself transformed into a demon. A human lost... or a human who can find himself?