序章

1. Origins, structure, and basic meaning

• Structure: Written 序章 and read じょしょう, it denotes a prologue before the main body of a work and figuratively the opening of a longer process.
• Basic usage: It introduces a mysterious letter in a story and frames a small success as the start of a long challenge.

2. Common pitfalls and similar expressions

• Literal prologue versus figurative beginning
  • It can be a named section of a work or a metaphor for only the first stage of what follows.