No Longer Human (1948, Ningen Shikkaku / A Shameful Life / Confessions of a Faulty Man) was an attack on the traditions of Japan, capturing the postwar crisis of Japanese cultural identity. Framed by an epilogue and prologue, the story is told in the form three notebooks left by Ōba Yōzō, whose calm exterior hides his tormented soul.
Osamu Dazai was a Japanese author who is considered one of the foremost fiction writers of 20th century Japan. A number of his most popular works, such as Shayō (The Setting Sun) and Ningen Shikkaku (No Longer Human), are considered modern-day classics in Japan.
Japanese novelist and a master storyteller, who became at the end of World War II the literary voice and literary hero of his generation. Dazai's life ended in double-suicide with his married mistress. In many books Dazai used biographical material from his own family background, and made his self-destructive life the subject of his books. 
Famous works of the author Osamu Dazai: The Setting Sun, Run, Melos!, Winter's firework, I heard it in this way, No Longer Human, Good-Bye.