View source for Nihon-shiki romanization

{{short description|Romanization system for transliterating the Japanese language into the Latin alphabet}}
{{distinguish|Nihon Shoki|Shoku Nihongi}}
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{{More citations needed|date=February 2009}}
{{More footnotes|date=April 2009}}
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{{Use Oxford spelling |date=April 2025}}
{{Use dmy dates |date=April 2025}}
{{Japanese writing}}
{{Use shortened footnotes |date=April 2025}}
{{nihongo|'''Nihon-shiki romanization'''|日本式ローマ字|Nihon-shiki rōmaji|lead=yes|{{lit|Japan-style [[Latin script|Roman letters]]|lk=yes}}}}, romanized as {{transliteration|ja|'''Nihonsiki'''}} in the system itself, is a [[romanization]] system for [[transliterating]] the [[Japanese language]] into the [[Latin alphabet]]. Among the major romanization systems for Japanese, it is the most regular one and has an almost [[Bijection|one-to-one relation]] to the [[kana]] writing system.

==History==
{{See also |Hiragana#Spelling–phonology correspondence |l1=Hiragana }}
It was invented by physicist [[Aikitu Tanakadate|Aikitsu Tanakadate]] (田中館 愛橘) in 1885,{{sfnp |Gottlieb |2010 |p=78 }} with the intention to replace the [[Hepburn romanization|Hepburn]] system of romanization.{{sfnp |Kent |Lancour |Daily |1978 |loc=Oriental Literature and Bibliography |p=[https://books.google.com/books?id=H1pNvzr_n98C&dq=Kunrei+tourist&pg=PA155 155] }} Tanakadate's intention was to replace the traditional [[kanji]] and [[kana]] system of writing Japanese completely by a romanized system, which he felt would make it easier for Japan to compete with Western countries. Since the system was intended for Japanese people to use to write their own language, it is much more regular than Hepburn romanization, and unlike Hepburn's system, it makes no effort to make itself easier to pronounce for English-speakers.{{citation needed|date=May 2013}}

Nihon-shiki was followed by [[Kunrei-shiki]], which was adopted in 1937, after a political debate over whether Nihon-shiki or [[Hepburn-shiki]] should be used by the Japanese government.{{sfnp |Gottlieb |2010 |p=78 }} Kunrei-shiki is nearly identical to Nihon-shiki, but it merges syllable pairs di/zi ぢ/じ, du/zu づ/ず, dya/zya ぢゃ/じゃ, dyu/zyu ぢゅ/じゅ, dyo/zyo ぢょ/じょ, wi/i ゐ/い, we/e ゑ/え, kwa/ka くゎ/か, and gwa/ga ぐゎ/が, whose pronunciations in Modern Standard Japanese are now identical. For example, the word かなづかい, rendered ''kana'''du'''kai'' in Nihon-shiki, is pronounced as ''kana'''zu'''kai''  in modern Japanese, and is romanized as such in Kunrei. The [[International Organization for Standardization]] has standardized Kunrei-shiki, under ISO 3602. The [[JSL romanization|JSL]] system, which is intended for use instructing foreign students of Japanese, is also based on Nihon-shiki. However, [[Yotsugana|some Japanese-speakers still distinguish di from zi and du from zu]] and so Nihon-shiki spelling is not entirely obsolete.

Nihon-shiki is considered the most regular of the romanization systems for the Japanese language because it maintains a strict "one kana, two letters" form. Because it has unique forms corresponding to each of the respective pairs of ''kana'' homophones listed above, it is the only formal system of romanization that can allow (almost) lossless ("round trip") mapping, but the standard does not mandate the precise spellings needed to distinguish ô 王/おう, ou 追う/おう and oo 大/おお.

==Romanization charts==

{| border="0" cellspacing="2px" cellpadding="2px" width="100%"
|-
!colspan="5" bgcolor="#BECFEB" valign=top align="center" | [[gozyûon]]
!colspan="3" bgcolor="#D4D4D4" valign=top align="center" | [[yôon]]
|-bgcolor="#BECFEB" valign=top align="center"
!あ/ア ''a''
!い/イ ''i''
!う/ウ ''u''
!え/エ ''e''
!お/オ ''o''
!bgcolor="#D4D4D4"|(''ya'')
!bgcolor="#D4D4D4"|(''yu'')
!bgcolor="#D4D4D4"|(''yo'')
|-
|colspan="8"|
|-bgcolor="#E7F5DE" valign=top align="center"
|か/カ ''ka''
|き/キ ''ki''
|く/ク ''ku''
|け/ケ ''ke''
|こ/コ ''ko''
|bgcolor="#F3F5DE"|きゃ/キャ ''kya''
|bgcolor="#F3F5DE"|きゅ/キュ ''kyu''
|bgcolor="#F3F5DE"|きょ/キョ ''kyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|さ/サ ''sa''
|し/シ ''si''
|す/ス ''su''
|せ/セ ''se''
|そ/ソ ''so''
|bgcolor="#F3F5DE"|しゃ/シャ ''sya''
|bgcolor="#F3F5DE"|しゅ/シュ ''syu''
|bgcolor="#F3F5DE"|しょ/ショ ''syo''
|-bgcolor="#E7F5DE" valign=top align="center"
|た/タ ''ta''
|ち/チ ''ti''
|つ/ツ ''tu''
|て/テ ''te''
|と/ト ''to''
|bgcolor="#F3F5DE"|ちゃ/チャ ''tya''
|bgcolor="#F3F5DE"|ちゅ/チュ ''tyu''
|bgcolor="#F3F5DE"|ちょ/チョ ''tyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|な/ナ ''na''
|に/ニ ''ni''
|ぬ/ヌ ''nu''
|ね/ネ ''ne''
|の/ノ ''no''
|bgcolor="#F3F5DE"|にゃ/ニャ ''nya''
|bgcolor="#F3F5DE"|にゅ/ニュ ''nyu''
|bgcolor="#F3F5DE"|にょ/ニョ ''nyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|は/ハ ''ha''
|ひ/ヒ ''hi''
|ふ/フ ''hu''
|へ/ヘ ''he''
|ほ/ホ ''ho''
|bgcolor="#F3F5DE"|ひゃ/ヒャ ''hya''
|bgcolor="#F3F5DE"|ひゅ/ヒュ ''hyu''
|bgcolor="#F3F5DE"|ひょ/ヒョ ''hyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|ま/マ ''ma''
|み/ミ ''mi''
|む/ム ''mu''
|め/メ ''me''
|も/モ ''mo''
|bgcolor="#F3F5DE"|みゃ/ミャ ''mya''
|bgcolor="#F3F5DE"|みゅ/ミュ ''myu''
|bgcolor="#F3F5DE"|みょ/ミョ ''myo''
|-bgcolor="#E7F5DE" valign=top align="center"
|や/ヤ ''ya''
|bgcolor="#E9E9E9"|
|ゆ/ユ ''yu''
|bgcolor="#E9E9E9"|
|よ/ヨ ''yo''
|bgcolor="#E9E9E9" colspan="3"|
|-bgcolor="#E7F5DE" valign=top align="center"
|ら/ラ ''ra''
|り/リ ''ri''
|る/ル ''ru''
|れ/レ ''re''
|ろ/ロ ''ro''
|bgcolor="#F3F5DE"|りゃ/リャ ''rya''
|bgcolor="#F3F5DE"|りゅ/リュ ''ryu''
|bgcolor="#F3F5DE"|りょ/リョ ''ryo''
|-bgcolor="#E7F5DE" valign=top align="center"
|わ/ワ ''wa''
|<span style="color:red;">ゐ/ヰ ''wi''</span>
|bgcolor="#E9E9E9"|
|<span style="color:red;">ゑ/ヱ ''we''</span>
|を/ヲ ''wo''
|bgcolor="#E9E9E9" colspan="3"|
|-bgcolor="#E7F5DE" valign=top align="center"
|bgcolor="#E9E9E9" colspan="4"|
|ん/ン ''n''
|bgcolor="#E9E9E9" colspan="3"|
|-
!colspan="8" | voiced sounds ([[dakuten]])
|-bgcolor="#E7F5DE" valign=top align="center"
|が/ガ ''ga''
|ぎ/ギ ''gi''
|ぐ/グ ''gu''
|げ/ゲ ''ge''
|ご/ゴ ''go''
|bgcolor="#F3F5DE"|ぎゃ/ギャ ''gya''
|bgcolor="#F3F5DE"|ぎゅ/ギュ ''gyu''
|bgcolor="#F3F5DE"|ぎょ/ギョ ''gyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|ざ/ザ ''za''
|じ/ジ ''zi''
|ず/ズ ''zu''
|ぜ/ゼ ''ze''
|ぞ/ゾ ''zo''
|bgcolor="#F3F5DE"|じゃ/ジャ ''zya''
|bgcolor="#F3F5DE"|じゅ/ジュ ''zyu''
|bgcolor="#F3F5DE"|じょ/ジョ ''zyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|だ/ダ ''da''
|ぢ/ヂ ''di''
|づ/ヅ ''du''
|で/デ ''de''
|ど/ド ''do''
|bgcolor="#F3F5DE"|ぢゃ/ヂャ ''dya''
|bgcolor="#F3F5DE"|ぢゅ/ヂュ ''dyu''
|bgcolor="#F3F5DE"|ぢょ/ヂョ ''dyo''
|-bgcolor="#E7F5DE" valign=top align="center"
|ば/バ ''ba''
|び/ビ ''bi''
|ぶ/ブ ''bu''
|べ/ベ ''be''
|ぼ/ボ ''bo''
|bgcolor="#F3F5DE"|びゃ/ビャ ''bya''
|bgcolor="#F3F5DE"|びゅ/ビュ ''byu''
|bgcolor="#F3F5DE"|びょ/ビョ ''byo''
|-bgcolor="#E7F5DE" valign=top align="center"
|ぱ/パ ''pa''
|ぴ/ピ ''pi''
|ぷ/プ ''pu''
|ぺ/ペ ''pe''
|ぽ/ポ ''po''
|bgcolor="#F3F5DE"|ぴゃ/ピャ ''pya''
|bgcolor="#F3F5DE"|ぴゅ/ピュ ''pyu''
|bgcolor="#F3F5DE"|ぴょ/ピョ ''pyo''
|-
|colspan="8"|
|-bgcolor="#E7F5DE" valign=top align="center"
|<span style="color:red;">くゎ/クヮ ''kwa''</span>
|bgcolor="#E9E9E9" colspan="4"|
|bgcolor="#E9E9E9" colspan="3"|
|-bgcolor="#E7F5DE" valign=top align="center"
|<span style="color:red;">ぐゎ/グヮ ''gwa''</span>
|bgcolor="#E9E9E9" colspan="4"|
|bgcolor="#E9E9E9" colspan="3"|
|}

===Notes===
*Letters in <span style="color:red;">red</span> are obsolete in modern Japanese.
*Even when ''he'' へ is used as a particle, it is written as ''he'', not ''e'' (Kunrei-shiki/Hepburn).
*Even when ''ha'' は is used as a particle, it is written as ''ha'', not ''wa''.
*Even when ''wo'' を is used as a particle, it is written as ''wo'', not ''o''.
*Long vowels are indicated by a [[circumflex accent]]: long '''o''' is written ''ô'', unlike Hepburn, which uses a [[macron (diacritic)|macron]].
*Syllabic '''n''' ん is written as ''n'' before consonants but as ''n{{'}}'' before vowels and ''y''.
*[[Geminate consonant]]s are always marked by doubling the consonant following the [[sokuon]] (っ).

== See also ==
* [[List of ISO romanizations]]

==References==
{{Reflist |20em}}

==Sources==
{{Refbegin |30em |indent=yes}}
*{{cite journal |last=Gottlieb |first=Nanette |date=January 2010 |url=https://www.cambridge.org/core/journals/journal-of-the-royal-asiatic-society/article/the-romaji-movement-in-japan/8652AD6C4CF1D7094BDF41FBF1545072 |title=The Rōmaji movement in Japan |journal=[[Journal of the Royal Asiatic Society]] |series=Third Series |volume=20 |issue=1 |pages=75–88 |publisher=[[Cambridge Journals]] |doi=10.1017/S1356186309990320 |url-access=subscription }}
*{{cite book |editor1-last=Kent |editor1-first=Allen |editor1-link=Allen Kent |editor2-last=Lancour |editor2-first=Harold |editor3-last=Daily|editor3-first=Jay Elwood |date=1978-04-01 |title=Encyclopedia of Library and Information Science |volume=21 |publisher=Marcel Dekker |isbn=0824720210 }}
{{Refend}}

==General references==
{{Refbegin |30em |indent=yes}}
*{{cite book |last=Kida |first=Jun'ichirō |year=1994 |chapter=Chapter 6 |title=Nihongo Daihakubutsukan |script-title=ja:日本語大博物館 |trans-title= |language=ja |publisher=Just System ({{langx|ja|ジャストシステム|Jasuto Shisutemu|label=none}}) |location=Tokyo
|isbn=4-88309-046-9 }}
{{Refend}}


{{Subject bar |auto=0 |portal1=Japan |portal2=Language }}
{{Japanese romanization}}
{{Japanese language}}

[[Category:Romanization of Japanese]]
[[Category:ISO 3602]]
[[Category:Japanese writing system]]