"No Longer Human" is a novel by Osamu Dazai, first published in 1948. It tells the story of Yozo Oba, a man who struggles with feelings of alienation and disconnection from society. The narrative is presented through a series of notebooks that reveal his inner turmoil and experiences, reflecting themes of identity and existential despair. The book is considered a classic of Japanese literature and is often regarded as a semi-autobiographical work, drawing from Dazai's own life. Its exploration of mental health and societal expectations resonates with many readers, making it a significant piece in the literary canon.