Where does “義妹” come from?

義妹 (Japanese) comes from Japanese 妹, from Japanese 人, from Proto-Japonic *pitə — one.

義妹 (Japanese): sister-in-law spouse's younger sister or younger brother's wife

Definitions

  1. sister-in-law spouse's younger sister or younger brother's wife

Ancestry of “義妹”, step by step

義妹 traces back through two separate lines of ancestry.

via Japanese 妹

StepLanguageWordMeaning
1Japanese妹a close female companion; one's own younger...
2Japanese人a person, human; an individual; mankind, people
3Proto-Japonic*pitəone

via Japanese 義

StepLanguageWordMeaning
1Japanese義justice; a situation which has a right and proper...
Every word from Proto-Japonic *pitə →Every word from Japanese 人 →Every word from Japanese 妹 →