This is the first translation into English of Torikaebaya monogatari, a twelfth-century work of unknown authorship that tells the unusual story of a brother and sister whose natural inclinations lead them at an early age to live as members of the opposite sex. The chronicle of their difficulties, especially the complications that arise in the course of their sexual encounters, concludes with the mature hero and heroine taking each other's place in society, thus returning to their original sexes. The Changelings is clearly among the best of the very few surviving examples of giko monogatari, a genre of narrative written in imitation of the great classical tales, most notably The Tale of Genji. It shares with others of its genre a relatively simple structure, a limited number of characters, an unusual - here sexual - problem as the basis of its plot, a nostalgic view of the past, and above all, numerous elements imitative of The Tale of Genji. Yet the story itself is quite different from Genji, and it achieves a freshness surprising in an imitative tale. The Introduction discusses Torikaebaya's critical history, dating and authorship, historical context, and problems of interpretation for the modern reader