遺書

1. Origins, structure, and basic meaning

• Structure: 遺書, read いしょ, combines leaving behind 遺 with writing 書 to denote a document left in anticipation of death.
• Basic usage: It denotes a written message or instructions left in anticipation of death, as in 家族への遺書.

2. Common pitfalls and similar expressions

• Scope and context
  • It can overlap with a legal will 遺言書, but 遺書 more broadly includes a farewell letter or personal final message.