Horace Walpole turns to the letters and argues that: Walpole's numerous letters are often used as a historical resource. In one, dating from 28 January 1754, he coined the word serendipity which he said was derived from a "silly fairy tale" he had read, "The Three Princes of Serendip". The oft-quoted epigram, "This world is a comedy to those that think, a tragedy to those that feel", is from a letter of Walpole's to Anne, Countess of Ossory, on 16 August 1776. The original, fuller version appeared in a letter to Sir Horace Mann on 31 December 1769: "I have often said,
Ef: A Fairy Tale of the Two year around the same time at the beginning of the first chapter of the story. Yuko hints of events that are revealed throughout "Ef: A Fairy Tale of the Two". After the conclusion of the first chapter, the story cycles back to the prologue and the talk between Yuko and Yu. Yuko ends with her talk about the events in the first chapter. At the end of the second chapter, the story shifts again to the scene with Yuko and Yu. Yuko finishes her talk on the events from the second chapter and says that she misses talking to Hiro,