Romanization of Japanese

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The romanization of Japanese is the use of Latin script to write the Japanese language.[1] This method of writing is sometimes referred to in Japanese as rōmaji (ローマ字, lit.'Roman letters', [ɾoːma(d)ʑi] or [ɾoːmaꜜ(d)ʑi]).

Japanese is normally written in a combination of logographic characters borrowed from Chinese (kanji) and syllabic scripts (kana) that also ultimately derive from Chinese characters.

There are several different romanization systems. The three main ones are Hepburn romanization, Kunrei-shiki romanization (ISO 3602) and Nihon-shiki romanization (ISO 3602 Strict). Variants of the Hepburn system are the most widely used.

Romanized Japanese may be used in any context where Japanese text is targeted at non-Japanese speakers who cannot read kanji or kana, such as for names on street signs and passports and in dictionaries and textbooks for foreign learners of the language. It is also used to transliterate Japanese terms in text written in English (or other languages that use the Latin script) on topics related to Japan, such as linguistics, literature, history, and culture.

All Japanese who have attended elementary school since World War II have been taught to read and write romanized Japanese. Therefore, almost all Japanese can read and write Japanese by using rōmaji. However, it is extremely rare in Japan to use it to write Japanese (except as an input tool on a computer or for special purposes like in some logo design), and most Japanese are more comfortable in reading kanji and kana.


The earliest Japanese romanization system was based on Portuguese orthography. It was developed around 1548 by a Japanese Catholic named Anjirō.[2][citation needed] Jesuit priests used the system in a series of printed Catholic books so that missionaries could preach and teach their converts without learning to read Japanese orthography. The most useful of these books for the study of early modern Japanese pronunciation and early attempts at romanization was the Nippo jisho, a Japanese–Portuguese dictionary written in 1603. In general, the early Portuguese system was similar to Nihon-shiki in its treatment of vowels. Some consonants were transliterated differently: for instance, the /k/ consonant was rendered, depending on context, as either c or q, and the /ɸ/ consonant (now pronounced /h/, except before u) as f; and so Nihon no kotoba ("The language of Japan") was spelled Nifon no cotoba. The Jesuits also printed some secular books in romanized Japanese, including the first printed edition of the Japanese classic The Tale of the Heike, romanized as Feiqe no monogatari, and a collection of Aesop's Fables (romanized as Esopo no fabulas). The latter continued to be printed and read after the suppression of Christianity in Japan (Chibbett, 1977).

From the mid-19th century onward, several systems were developed, culminating in the Hepburn system, named after James Curtis Hepburn who used it in the third edition of his Japanese–English dictionary, published in 1887. The Hepburn system included representation of some sounds that have since changed. For example, Lafcadio Hearn's book Kwaidan shows the older kw- pronunciation; in modern Hepburn romanization, this would be written Kaidan (lit.'ghost tales').[citation needed]

As a replacement for the Japanese writing system[edit]

In the Meiji era (1868–1912), some Japanese scholars advocated abolishing the Japanese writing system entirely and using rōmaji instead. The Nihon-shiki romanization was an outgrowth of that movement. Several Japanese texts were published entirely in rōmaji during this period, but it failed to catch on. Later, in the early 20th century, some scholars devised syllabary systems with characters derived from Latin (rather like the Cherokee syllabary) that were even less popular since they were not based on any historical use of the Latin script.

Today, the use of Nihon-shiki for writing Japanese is advocated by the Oomoto sect[3] and some independent organizations.[4] During the Allied occupation of Japan, the government of the Supreme Commander for the Allied Powers (SCAP) made it official policy to romanize Japanese. However, that policy failed and a more moderate attempt at Japanese script reform followed.

Modern systems[edit]


Old sign from the JNR era at Toyooka Station shows inconsistent romanization. Although in principle Hepburn is used, Kokuhu is the kunrei-shiki form (which would be Kokufu in Hepburn).

Hepburn romanization generally follows English phonology with Romance vowels. It is an intuitive method of showing Anglophones the pronunciation of a word in Japanese. It was standardized in the United States as American National Standard System for the Romanization of Japanese (Modified Hepburn), but that status was abolished on October 6, 1994. Hepburn is the most common romanization system in use today, especially in the English-speaking world.

The Revised Hepburn system of romanization uses a macron to indicate some long vowels and an apostrophe to note the separation of easily confused phonemes (usually, syllabic n from a following naked vowel or semivowel). For example, the name じゅんいちろう is written with the kana characters ju-n-i-chi-ro-u, and romanized as Jun'ichirō in Revised Hepburn. Without the apostrophe, it would not be possible to distinguish this correct reading from the incorrect ju-ni-chi-ro-u (じゅにちろう). This system is widely used in Japan and among foreign students and academics.


Nihon-shiki romanization was originally invented as a method for Japanese to write their own language in Latin characters, rather than to transcribe it for Westerners as Hepburn was. It follows the Japanese syllabary very strictly, with no adjustments for changes in pronunciation. It has also been standardized as ISO 3602 Strict. Also known as Nippon-shiki, rendered in the Nihon-shiki style of romanization the name is either Nihon-siki or Nippon-siki.


Kunrei-shiki romanization is a slightly modified version of Nihon-shiki which eliminates differences between the kana syllabary and modern pronunciation. For example, the characters and are pronounced identically in modern Japanese, and thus Kunrei-shiki and Hepburn ignore the difference in kana and represent the sound in the same way (zu). Nihon-shiki, on the other hand, will romanize as du, but as zu. Similarly for the pair and , they are both zi in Kunrei-shiki and ji in Hepburn, but are zi and di respectively in Nihon-shiki. See the table below for full details.

Kunrei-shiki has been standardized by the Japanese Government and the International Organization for Standardization as ISO 3602. Kunrei-shiki is taught to Japanese elementary school students in their fourth year of education.

Written in Kunrei-shiki, the name of the system would be rendered Kunreisiki.

Other variants[edit]

It is possible to elaborate these romanizations to enable non-native speakers to pronounce Japanese words more correctly. Typical additions include tone marks to note the Japanese pitch accent and diacritic marks to distinguish phonological changes, such as the assimilation of the moraic nasal /ɴ/ (see Japanese phonology).


JSL is a romanization system based on Japanese phonology, designed using the linguistic principles used by linguists in designing writing systems for languages that do not have any. It is a purely phonemic system, using exactly one symbol for each phoneme, and marking the pitch accent using diacritics. It was created for Eleanor Harz Jorden's system of Japanese language teaching. Its principle is that such a system enables students to internalize the phonology of Japanese better. Since it does not have any of the other systems' advantages for non-native speakers, and the Japanese already have a writing system for their language, JSL is not widely used outside the educational environment.

Non-standard romanization[edit]

In addition to the standardized systems above, there are many variations in romanization, used either for simplification, in error or confusion between different systems, or for deliberate stylistic reasons.

Notably, the various mappings that Japanese input methods use to convert keystrokes on a Roman keyboard to kana often combine features of all of the systems; when used as plain text rather than being converted, these are usually known as wāpuro rōmaji. (Wāpuro is a blend of do purosessā word processor.) Unlike the standard systems, wāpuro rōmaji requires no characters from outside the ASCII character set.

While there may be arguments in favour of some of these variant romanizations in specific contexts, their use, especially if mixed, leads to confusion when romanized Japanese words are indexed. This confusion never occurs when inputting Japanese characters with a word processor, because input Latin letters are transliterated into Japanese kana as soon as the IME processes what character is input.

Long vowels[edit]

In addition, the following three "non-Hepburn rōmaji" (非ヘボン式ローマ字, hi-Hebon-shiki rōmaji) methods of representing long vowels are authorized by the Japanese Foreign Ministry for use in passports.[5]

  • oh for おお or おう (Hepburn ō).
  • oo for おお or おう. This is valid JSL romanization. For Hepburn romanization, it is not a valid romanization if the long vowel belongs within a single word.
  • ou for おう. This is also an example of wāpuro rōmaji.

Example words written in each romanization system[edit]

English Japanese Kana spelling Romanization
Revised Hepburn Kunrei-shiki Nihon-shiki
Roman characters ローマ字 ローマじ rōmaji rômazi rômazi
Mount Fuji 富士山 ふじさん Fujisan Huzisan Huzisan
tea お茶 おちゃ ocha otya otya
governor 知事 ちじ chiji tizi tizi
to shrink 縮む ちぢむ chijimu tizimu tidimu
to continue 続く つづく tsuzuku tuzuku tuduku

Differences among romanizations[edit]

This chart shows in full the three main systems for the romanization of Japanese: Hepburn, Nihon-shiki and Kunrei-shiki:

Hiragana Katakana Hepburn Nihon-shiki Kunrei-shiki IPA
u ɯ
ki kʲi
きゃ キャ kya kʲa
きゅ キュ kyu kʲɯ
きょ キョ kyo kʲo
shi si ɕi
しゃ シャ sha sya ɕa
しゅ シュ shu syu ɕɯ
しょ ショ sho syo ɕo
chi ti tɕi
tsu tu tsɯ
ちゃ チャ cha tya tɕa
ちゅ チュ chu tyu tɕɯ
ちょ チョ cho tyo tɕo
ni ɲi
にゃ ニャ nya ɲa
にゅ ニュ nyu ɲɯ
にょ ニョ nyo ɲo
hi çi
fu hu ɸɯ
ひゃ ヒャ hya ça
ひゅ ヒュ hyu çɯ
ひょ ヒョ hyo ço
mi mʲi
みゃ ミャ mya mʲa
みゅ ミュ myu mʲɯ
みょ ミョ myo mʲo
ya ja
yo jo
ra ɾa
ri ɾʲi
ru ɾɯ
re ɾe
ro ɾo
りゃ リャ rya ɾʲa
りゅ リュ ryu ɾʲu
りょ リョ ryo ɾʲo
wa wa~ɰa
i wi i
e we e
o wo o
ゐゃ ヰャ iya wya iya
ゐゅ ヰュ iyu wyu iyu
ゐょ ヰョ iyo wyo iyo
n-n'(-m) n-n' m~n~ŋ~ɴ
gi gʲi
ぎゃ ギャ gya gʲa
ぎゅ ギュ gyu gʲɯ
ぎょ ギョ gyo gʲo
za za~dza
ji zi ʑi~dʑi
zu zɯ~dzɯ
ze ze~dze
zo zo~dzo
じゃ ジャ ja zya ʑa~dʑa
じゅ ジュ ju zyu ʑɯ~dʑɯ
じょ ジョ jo zyo ʑo~dʑo
ji di zi ʑi~dʑi
zu du zu zɯ~dzɯ
ぢゃ ヂャ ja dya zya ʑa~dʑa
ぢゅ ヂュ ju dyu zyu ʑɯ~dʑɯ
ぢょ ヂョ jo dyo zyo ʑo~dʑo
bi bʲi
びゃ ビャ bya bʲa
びゅ ビュ byu bʲɯ
びょ ビョ byo bʲo
pi pʲi
ぴゃ ピャ pya pʲa
ぴゅ ピュ pyu pʲɯ
ぴょ ピョ pyo pʲo
vu βɯ

This chart shows the significant differences among them. Despite the International Phonetic Alphabet, the /j/ sound in , , and are never romanized with the letter J.

Kana Revised Hepburn Nihon-shiki Kunrei-shiki
うう ū û
おう, おお ō ô
shi si
しゃ sha sya
しゅ shu syu
しょ sho syo
ji zi
じゃ ja zya
じゅ ju zyu
じょ jo zyo
chi ti
tsu tu
ちゃ cha tya
ちゅ chu tyu
ちょ cho tyo
ji di zi
zu du zu
ぢゃ ja dya zya
ぢゅ ju dyu zyu
ぢょ jo dyo zyo
fu hu
i wi i
e we e
o wo o
n, n' ( m) n n'


Japanese is written without spaces between words, and in some cases, such as compounds, it may not be completely clear where word boundaries should lie, resulting in varying romanization styles. For example, 結婚する, meaning "to marry", and composed of the noun 結婚 (kekkon, "marriage") combined with する (suru, "to do"), is romanized as one word kekkonsuru by some authors but two words kekkon suru by others.

Kana without standardized forms of romanization[edit]

There is no universally accepted style of romanization for the smaller versions of the vowels and y-row kana when used outside the normal combinations (きゃ, きょ, ファ etc.), nor for the sokuon or small tsu kana っ/ッ when it is not directly followed by a consonant. Although these are usually regarded as merely phonetic marks or diacritics, they do sometimes appear on their own, such as at the end of sentences, in exclamations, or in some names. The detached sokuon, representing a final glottal stop in exclamations, is sometimes represented as an apostrophe or as t; for example, あっ! might be written as a'! or at!.[citation needed]

Historical romanizations[edit]

1603: Vocabvlario da Lingoa de Iapam (1603)
1604: Arte da Lingoa de Iapam (1604–1608)
1620: Arte Breve da Lingoa Iapoa (1620)
1848: Kaisei zoho Bango sen[6] (1848)
1603 a i, j, y v, u ye vo, uo
1604 i v vo
1620 y
1848 i woe e o
きゃ きょ くゎ
1603 ca qi, qui cu, qu qe, que co qia qio, qeo qua
1604 qui que quia quio
1620 ca, ka ki cu, ku ke kia kio
1848 ka kfoe ko
ぎゃ ぎゅ ぎょ ぐゎ
1603 ga gui gu, gv gue go guia guiu guio gua
1604 gu
1620 ga, gha ghi gu, ghu ghe go, gho ghia ghiu ghio
1848 ga gi gfoe ge go
しゃ しゅ しょ
1603 sa xi su xe so xa xu xo
1848 si sfoe se
じゃ じゅ じょ
1603 za ii, ji zu ie, ye zo ia, ja iu, ju io, jo
1604 ji ia ju jo
1620 ie iu io
1848 zi zoe ze
ちゃ ちゅ ちょ
1603 ta chi tçu te to cha chu cho
1848 tsi tsoe
ぢゃ ぢゅ ぢょ
1603 da gi zzu de do gia giu gio
1604 dzu
1848 dsi dsoe
にゃ にゅ にょ
1603 na ni nu ne no nha nhu, niu nho, neo
1604 nha nhu nho
1848 noe
ひゃ ひゅ ひょ
1603 fa fi fu fe fo fia fiu fio, feo
1604 fio
1848 ha hi foe he ho
びゃ びゅ びょ
1603 ba bi bu be bo bia biu bio, beo
1620 bia biu
1848 boe
ぴゃ ぴゅ ぴょ
1603 pa pi pu pe po pia pio
1620 pia
1848 poe
みゃ みょ
1603 ma mi mu me mo mia, mea mio, meo
1620 mio
1848 moe
1603 ya yu yo
りゃ りゅ りょ
1603 ra ri ru re ro ria, rea riu rio, reo
1604 rio
1620 riu
1848 roe
1603 va, ua vo, uo
1604 va y ye vo
1848 wa wi ije, ÿe wo
1603 n, m, ˜ (tilde)
1604 n
1620 n, m
1603 -t, -cc-, -cch-, -cq-, -dd-, -pp-, -ss-, -tt, -xx-, -zz-
1604 -t, -cc-, -cch-, -pp-, -cq-, -ss-, -tt-, -xx-
1620 -t, -cc-, -cch-, -pp-, -ck-, -cq-, -ss-, -tt-, -xx-

Roman letter names in Japanese[edit]

The list below shows the Japanese readings of letters in Katakana, for spelling out words, or in acronyms. For example, NHK is read enu-eichi-kē (エヌ・エイチ・ケー). These are the standard names, based on the British English letter names (so Z is from zed, not zee), but in specialized circumstances, names from other languages may also be used. For example, musical keys are often referred to by the German names, so that B is called (べー) from German B (German: [beː]).

  • A; ē (エー, sometimes pronounced ei, エイ)
  • B; (ビー)
  • C; shī (シー, sometimes pronounced , スィー)
  • D; (ディー, sometimes pronounced , デー)
  • E; ī (イー)
  • F; efu (エフ)
  • G; (ジー)
  • H; eichi or etchi (エイチ or エッチ)
  • I; ai (アイ)
  • J; (ジェー, sometimes pronounced jei, ジェイ)
  • K; (ケー, sometimes pronounced kei, ケイ)
  • L; eru (エル)
  • M; emu (エム)
  • N; enu (エヌ)
  • O; ō (オー)
  • P; (ピー)
  • Q; kyū (キュー)
  • R; āru (アール)
  • S; esu (エス)
  • T; (ティー)
  • U; (ユー)
  • V; bui or (ブイ or ヴィー)
  • W; daburyū (ダブリュー)
  • X; ekkusu (エックス)
  • Y; wai (ワイ)
  • Z; zetto (ゼット)

Sources: Kōjien (7th edition), Daijisen (online version).

Note: Daijisen does not mention the name , while Kōjien does.

See also[edit]



  1. ^ Walter Crosby Eells (May 1952). "Language Reform in Japan". The Modern Language Journal. 36 (5): 210–213. doi:10.1111/j.1540-4781.1952.tb06122.x. JSTOR 318376.
  2. ^ "What is Romaji? Everything you need to know about Romaji Everything you need to know about Romaji". 17 July 2020.
  3. ^ "". 2000-02-07. Retrieved 2011-02-25.
  4. ^ "". Retrieved 2011-02-25.
  5. ^ "ヘボン式ローマ字と異なる場合(非ヘボン式ローマ字)". Kanagawa Prefectural Government. Retrieved 2018-08-19.
  6. ^ "Kaisei zoho Bango sen. (Lager image 104-002) | Japan-Netherlands Exchange in the Edo Period".


  • Chibbett, David (1977). The History of Japanese Printing and Book Illustration. Kodansha International Ltd. ISBN 0-87011-288-0.
  • Jun'ichirō Kida (紀田順一郎, Kida Jun'ichirō) (1994). Nihongo Daihakubutsukan (日本語大博物館) (in Japanese). Just System (ジャストシステム, Jasuto Shisutem). ISBN 4-88309-046-9.
  • Tadao Doi (土井忠生) (1980). Hōyaku Nippo Jisho (邦訳日葡辞書) (in Japanese). Iwanami Shoten (岩波書店).
  • Tadao Doi (土井忠生) (1955). Nihon Daibunten (日本大文典) (in Japanese). Sanseido (三省堂).
  • Mineo Ikegami (池上岑夫) (1993). Nihongo Shōbunten (日本語小文典) (in Japanese). Iwanami Shoten (岩波書店).
  • Hiroshi Hino (日埜博) (1993). Nihon Shōbunten (日本小文典) (in Japanese). Shin-Jinbutsu-Ôrai-Sha (新人物往来社).

Further reading[edit]

External links[edit]