noun
boy; young male
Typically refers to a male child or adolescent, often in contrast to 女子 (girl). Common in school, sports, and demographic contexts.
このクラスには男子が15人いる。
There are 15 boys in this class.
男子トイレはあちらです。
The boys' restroom is over there.
noun
Used for adult males, often in formal, statistical, or categorical contexts (e.g., 男子社員, 男子学生). In casual speech, 男性 is more common for 'man'.
この会社の男子社員はみんなスーツを着ている。
All the male employees at this company wear suits.
男子マラソンの優勝者はケニアの選手だった。
The winner of the men's marathon was a Kenyan athlete.