O (kana)
Character of the Japanese writing system
O (hiragana: お, katakana: オ) is one of the Japanese kana, each of which represents one mora. In the modern Japanese system of alphabetical order, they occupy the fifth place 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 [o].
01Derivation
お and オ originate, via man'yōgana, from the kanji 於.

02Variant forms
Scaled-down versions of the kana (ぉ, ォ) are used to express morae foreign to the Japanese language, such as フォ (fo).

03Stroke order
The hiragana お is made with three strokes:
- A horizontal line from left to right.
- A stroke consisting of a vertical line, a small diagonal line going upwards and to the left, and an open curve heading right and downwards.
- A small curved stroke on the right.
The katakana オ is made with three strokes:
- At the top, a horizontal stroke from left to right.
- A downward vertical stroke cutting through the first stroke, with a small hook at the end facing left.
- At the intersection of the first two strokes, a diagonal line going downwards and to the left.

04Other communicative representations
| Japanese radiotelephony alphabet | Wabun code |
| 大阪のオ Ōsaka no "O" |
▄ ▄▄▄ ▄ ▄ ▄ ⓘ |
| Japanese Navy Signal Flag | Japanese semaphore | Japanese manual syllabary (fingerspelling) | Braille dots-24 Japanese Braille |
- Full Braille representation
| お / オ in Japanese Braille | ||
|---|---|---|
| お / オ o | おう / オー ō/ou | +う / +ー chōon* |
* When lengthening "-o" morae in Japanese braille, a chōon is always used, as in standard katakana usage instead of adding an お / オ.
| Preview | お | オ | オ | ㋔ | ||||
|---|---|---|---|---|---|---|---|---|
| Unicode name | HIRAGANA LETTER O | KATAKANA LETTER O | HALFWIDTH KATAKANA LETTER O | CIRCLED KATAKANA O | ||||
| Encodings | decimal | hex | dec | hex | dec | hex | dec | hex |
| Unicode | 12362 | U+304A | 12458 | U+30AA | 65397 | U+FF75 | 13012 | U+32D4 |
| UTF-8 | 227 129 138 | E3 81 8A | 227 130 170 | E3 82 AA | 239 189 181 | EF BD B5 | 227 139 148 | E3 8B 94 |
| Numeric character reference | お | お | オ | オ | オ | オ | ㋔ | ㋔ |
| Shift JIS | 130 168 | 82 A8 | 131 73 | 83 49 | 181 | B5 | ||
| EUC-JP | 164 170 | A4 AA | 165 170 | A5 AA | 142 181 | 8E B5 | ||
| GB 18030 | 164 170 | A4 AA | 165 170 | A5 AA | 132 49 151 55 | 84 31 97 37 | 129 57 210 48 | 81 39 D2 30 |
| EUC-KR / UHC | 170 170 | AA AA | 171 170 | AB AA | ||||
| Big5 (non-ETEN kana) | 198 174 | C6 AE | 199 66 | C7 42 | ||||
| Big5 (ETEN / HKSCS) | 198 240 | C6 F0 | 199 166 | C7 A6 | ||||
| Preview | ぉ | ォ | ォ | |||
|---|---|---|---|---|---|---|
| Unicode name | HIRAGANA LETTER SMALL O | KATAKANA LETTER SMALL O | HALFWIDTH KATAKANA LETTER SMALL O | |||
| Encodings | decimal | hex | dec | hex | dec | hex |
| Unicode | 12361 | U+3049 | 12457 | U+30A9 | 65387 | U+FF6B |
| UTF-8 | 227 129 137 | E3 81 89 | 227 130 169 | E3 82 A9 | 239 189 171 | EF BD AB |
| Numeric character reference | ぉ | ぉ | ォ | ォ | ォ | ォ |
| Shift JIS | 130 167 | 82 A7 | 131 72 | 83 48 | 171 | AB |
| EUC-JP | 164 169 | A4 A9 | 165 169 | A5 A9 | 142 171 | 8E AB |
| GB 18030 | 164 169 | A4 A9 | 165 169 | A5 A9 | 132 49 150 55 | 84 31 96 37 |
| EUC-KR / UHC | 170 169 | AA A9 | 171 169 | AB A9 | ||
| Big5 (non-ETEN kana) | 198 173 | C6 AD | 199 65 | C7 41 | ||
| Big5 (ETEN / HKSCS) | 198 239 | C6 EF | 199 165 | C7 A5 | ||

Sources and credits
This article is adapted from the Wikipedia article “O (kana)”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- Hiragana お stroke order animation.gif by Sirgazil, CC0
- Katakana オ stroke order animation.gif by Sirgazil, CC0
- お-bw.png by Made by me, M4RC0, using Photoshop. We are making this kind of picture following the protocol of the section : Bitmap Image (PNG), CC BY-SA 2.5
- オ-bw.png by Made by me, M4RC0, using Photoshop. We are making this kind of picture following the protocol of the section : Bitmap Image (PNG), CC BY-SA 2.0
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