When did the "wu" character drop out of use?


In the last century, the [ゐ and ゑ characters were
eliminated](https://japanese.stackexchange.com/questions/88/why-were-and-
eliminated) from common use. But it seems like there used to also be a "wu"
character that has since been lost. Given that it's a lot harder to find
information about "wu", I assume it vanished much earlier.

Around when did the pronunciation and written character for "wu" drop out of
use?




The [English Wikipedia article on Kana](http://en.wikipedia.org/wiki/Kana)
suggests that there has never been a "wu" sound in Japanese.

> There are no kana for Ye, Yi or Wu, as corresponding syllables do not occur
> in Japanese natively[.]

The [Japanese Wikipedia article on the sound that would be
"wu"](http://ja.wikipedia.org/wiki/%E3%82%8F%E8%A1%8C%E3%81%86) confirms this.

> 日本語では「[w]」の子音と「[u]」の母音は共に/u/であるため、「う」の発音と同じになり、「う」と区別されない。
>
> Because in Japanese the consonant "w" and the vowel "u" both share the /u/
> sound, "wu" becomes the same pronunciation as "u" and the two sounds cannot
> be distinguished.

[This page](https://archive.is/MTXy) gives information on why there is a kana
for "wu" (于).

>
> 明治初期の国語教育では「五十音図」優位の見地から、表②のように「[yi]」「[ye]」「于」という文字を無理やり当てた教科書が出されたこともあったようだ。
>
> Because of the "Fifty Sounds" view that was ascendant in Japanese language
> teaching at the beginning of the Meiji period, apparently some textbooks
> even forced kana on yi, ye, and wu, as you can see in figure 2.

The Japanese Wikipedia pages on
[ye](http://ja.wikipedia.org/wiki/%E3%83%A4%E8%A1%8C%E3%82%A8) and
[yi](http://ja.wikipedia.org/wiki/%E3%83%A4%E8%A1%8C%E3%82%A4) seem to give
more information.




The [English Wikipedia article on Kana](http://en.wikipedia.org/wiki/Kana)
suggests that there has never been a "wu" sound in Japanese.

> There are no kana for Ye, Yi or Wu, as corresponding syllables do not occur
> in Japanese natively[.]

The [Japanese Wikipedia article on the sound that would be
"wu"](http://ja.wikipedia.org/wiki/%E3%82%8F%E8%A1%8C%E3%81%86) confirms this.

> 日本語では「[w]」の子音と「[u]」の母音は共に/u/であるため、「う」の発音と同じになり、「う」と区別されない。
>
> Because in Japanese the consonant "w" and the vowel "u" both share the /u/
> sound, "wu" becomes the same pronunciation as "u" and the two sounds cannot
> be distinguished.

[This page](https://archive.is/MTXy) gives information on why there is a kana
for "wu" (于).

>
> 明治初期の国語教育では「五十音図」優位の見地から、表②のように「[yi]」「[ye]」「于」という文字を無理やり当てた教科書が出されたこともあったようだ。
>
> Because of the "Fifty Sounds" view that was ascendant in Japanese language
> teaching at the beginning of the Meiji period, apparently some textbooks
> even forced kana on yi, ye, and wu, as you can see in figure 2.

The Japanese Wikipedia pages on
[ye](http://ja.wikipedia.org/wiki/%E3%83%A4%E8%A1%8C%E3%82%A8) and
[yi](http://ja.wikipedia.org/wiki/%E3%83%A4%E8%A1%8C%E3%82%A4) seem to give
more information.

