N (kana) in the context of む

Mu (hiragana: む, katakana: ム) is one of the Japanese kana, which each represent one mora. The hiragana is written with three strokes, while the katakana is written with two. Both represent [mɯ].

In older Japanese texts until the spelling reforms of 1900, む was also used to transcribe the nasalized [ɴ]. Since the reforms, it is replaced in such positions with ん.