む in the context of N (kana)

In the Japanese language, the gojūon (五十音; Japanese pronunciation: [ɡo(d)ʑɯꜜːoɴ], lit. 'fifty sounds') is a traditional system ordering kana characters by their component phonemes, roughly analogous to alphabetical order. The "fifty" (gojū) in its name refers to the 5×10 grid in which the characters are displayed. Each kana, which may be a hiragana or katakana character, corresponds to one sound in Japanese. As depicted at the right using hiragana characters, the sequence begins with あ (a), い (i), う (u), え (e), お (o), then continues with か (ka), き (ki), く (ku), け (ke), こ (ko), and so on and so forth for a total of ten rows of five columns.

Although nominally containing 50 characters, the grid is not completely filled, and, further, there is an extra character added outside the grid at the end: with 5 gaps and 1 extra character, the current number of distinct kana in a moraic chart in modern Japanese is therefore 46. Some of these gaps have always existed as gaps in sound: there was no yi or wu even in Old Japanese, with the kana for i and u doubling up for those phantom values. Ye persisted long enough for kana to be developed for it, but disappeared in Early Middle Japanese, having merged with e. Much later, with the spelling reforms after World War II, the kana for wi and we were replaced with i and e, the sounds they had merged with. The kana for moraic n (hiragana ん) is not part of the grid, as it was introduced long after the gojūon ordering was devised. (Previously mu (hiragana む) was used for this sound.)