実じつ妹まい

noun

biological younger sister

Used to specify a younger sister by blood, as opposed to a sister-in-law, stepsister, or close friend called 妹.

• 彼かの女じょは私わたしの実じつ妹まいです。

  She is my biological younger sister.

• 実じつ妹まいと義ぎ妹まいでは、やはり接せっし方ほうが違ちがう。

  I naturally interact differently with my biological younger sister than with my sister-in-law.