実じっ兄けい

noun

biological older brother; real older brother

Used to specify a blood-related older brother, as opposed to a brother-in-law (義兄) or a sworn brother. Common in family registers, formal introductions, and when clarifying family relationships.

• 彼かれは私わたしの実じっ兄けいです。

  He is my biological older brother.

• 実じっ兄けいと義ぎ兄けいを間ま違ちがえないでください。

  Please don't confuse my real older brother with my brother-in-law.