U (kana)

Both う and ウ originate, via man'yōgana, from the kanji 宇 (pronounced u and meaning space).

Scaled-down versions of the characters (ぅ, ゥ) are used to create new morae that do not exist in the Japanese language, such as トゥ (tu). This convention is relatively new, and many older loanwords do not use it. For example, in the phrase Tutankhamun's cartouche, the recent loan cartouche uses the new phonetic technique, but the older loan Tutankhamun uses ツ (tsu) as an approximation:

The character う is also used, in its full-sized form, to lengthen "o" sounds. For example, the word 構想 is written in hiragana as こうそう (kousou), pronounced kōsō. In a few words the character お (o) is used instead for morphological or historical reasons.

The character ウ can take dakuten to form ヴ (vu), a sound foreign to the Japanese language and traditionally approximated by ブ (bu).

In hentaigana a variant of う is appeared that retains cursive Kanji 宇.

Stroke order in writing う

Stroke order in writing ウ

Stroke order in writing う

The hiragana う is written in two strokes:

1. At the top of the character, a short diagonal crook: proceeding diagonally downwards from the left, then reversing direction and ending at the lower left.
2. A broad curving stroke: beginning at the left, rising slightly, then curving back and ending at the left.

Stroke order in writing ウ

The katakana ウ is written in three strokes:

1. At the top of the character, a short vertical stroke, written from top to bottom.
2. A similar stroke, but lower and positioned at the left.
3. A broad angled stroke: beginning as a horizontal line written from left to right, then reversing direction and proceeding downwards from right to left as a curved diagonal. The horizontal line must touch both the other strokes. Apart from the short diagonal, the character is identical to フ.