In Japanese writing, the kana お (hiragana) and オ (katakana) occupy the fifth place, between え and か, in the modern Gojūon (五十音) system of collating kana. In the Iroha, they occupy the 27th, between の and く. In the table at right (ordered by columns, from right to left), お lies in the first column (あ行, "column A") and the fifth row (お段, "row O"). Both represent Close-mid back rounded vowel.

Derivation

お and オ originate, via man'yōgana, from the kanji 於.

Variant forms

Scaled-down versions of the kana (ぉ, ォ) are used to express morae foreign to the Japanese language, such as フォ (fo).

Stroke order

The hiragana お is made with three strokes: The katakana オ is made with three strokes:

Other communicative representations