主人公

1. Origins, structure, and basic meaning

• Structure: 主人公 (しゅじんこう) is the central character in a story. 主人公は makes the character the topic; 主人公の決断 names an action belonging to that character.
• Basic usage: One example gives the protagonist's upbringing, while the other focuses on a surprising decision that affected the audience.

2. Common pitfalls and similar expressions

• Background of the protagonist and the protagonist's decision
  • 主人公は directly predicates the character, but after 主人公の the head noun is 決断. A protagonist should not automatically be equated with the narrator or actor.