Dazai Osamu wrote The Fairy Tale Book (Otogizōshi) in the last months of the Pacific War. The traditional tales upon which Dazai's retellings are based are well known to every Japanese schoolchild, but this is no children's book. In Dazai's hands such stock characters as the kindhearted Oji-san to Oba-san ("Grandmother and Grandfather"), the mischievous tanuki badger, the fearsome Oni ogres, the greedy old man, the "tongue-cut" sparrow, and of course Urashima Taro (the Japanese Rip van Winkle) become complex individuals facing difficult and nuanced moral dilemmas. The resulting stories are thought-provoking, slyly subversive, and often hilarious.

In spite of the "gloom and doom" atmosphere always cited in reviews of The Setting Sun and the later No Longer Human, though, Dazai's cutting wit and rich humor are evident in the entire body of his work. His literature depicts the human condition in painfully blunt and realistic terms, but, like life itself, is often accompanied by a smile.