# O (kana)

kana gojūon :
| wa | ra | ya | ma | ha | na | ta | sa | ka | a |
| wi | ri | (yi) | mi | hi | ni | chi | shi | ki | i |
| (wu) | ru | yu | mu | fu | nu | tsu | su | ku | u |
| we | re | (ye) | me | he | ne | te | se | ke | e |
| wo | ro | yo | mo | ho | no | to | so | ko | o |
| | | | n | | | | | | |
Kana modifiers and marks :
sokuonfu (gemination)
yōon (palatalization)
chōonpu (vowel lengthener)
Iteration marks
dakuten/handakuten (voiced & semi-voiced marks) :
Multi-moraic kana :
iu
kashiko
koto
sama
shite
toki
tomo
nari
mairasesoro
yori :
vte :
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.
| Form | Rōmaji | Hiragana | Katakana |
| Normal a/i/u/e/o (あ行 a-gyō) | o | お | オ |
| Normal a/i/u/e/o (あ行 a-gyō) | ou oo ō | おう, おぅ おお, おぉ おー | オウ, オゥ オオ, オォ オー |

## 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

| Stroke order in writing お | Stroke order in writing オ |
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.

## Other 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.
* Computer encodings
Character information :
| Preview | お | お | オ | オ | ｵ | ｵ | ㋔ | ㋔ |
| Unicode name | HIRAGANA LETTER O | HIRAGANA LETTER O | KATAKANA LETTER O | KATAKANA LETTER O | HALFWIDTH KATAKANA LETTER O | HALFWIDTH KATAKANA LETTER O | CIRCLED KATAKANA 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 | &#12362; | &#x304A; | &#12458; | &#x30AA; | &#65397; | &#xFF75; | &#13012; | &#x32D4; |
| 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 | | | | |
Character information :
| Preview | ぉ | ぉ | ォ | ォ | ｫ | ｫ |
| Unicode name | HIRAGANA LETTER SMALL O | HIRAGANA LETTER SMALL O | KATAKANA LETTER SMALL O | KATAKANA LETTER SMALL O | HALFWIDTH 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 | &#12361; | &#x3049; | &#12457; | &#x30A9; | &#65387; | &#xFF6B; |
| 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 | | |