Nihon-shiki romanization

Nihon-shiki or Nippon-shiki Rōmaji (Japanese: 日本式ローマ字, "Japan-style"; romanized as Nihon-siki or Nippon-siki in Nippon-shiki itself) is a romanization system for transliterating the Japanese language into the Latin alphabet. In discussion about romaji, it is abbreviated as Nihon-shiki or Nippon-shiki. Among the major romanization systems for Japanese, Nippon-shiki is the most regular, and has a one-to-one relation to the kana writing systems. In practice, Nippon-shiki has been largely supplanted by Hepburn romanization.

It was invented by physicist Aikitsu Tanakadate (田中館 愛橘) in 1885, with the intention to replace the Hepburn system of romanization. Tanakadate's intention was to completely replace the traditional kanji and kana system of writing Japanese with a romanized system, which he felt would make it easier for Japanese people 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.

Nippon-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. Kunrei is otherwise nearly identical, but it merges the 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, gwa/ga ぐゎ/が, whose pronunciations in modern standard Japanese have become identical. For example, the word かなづかい, rendered kanadukai in Nippon-shiki, is pronounced as kanazukai in modern Japanese and romanized as such in Kunrei.

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