Nihon-shiki Romanization - History

History

It was invented by physicist Aikitsu Tanakadate (田中館 愛橘 Tanakadate Aikitsu) in 1885, and postdates 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. 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.

Nippon-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 lossless ("round trip") mapping, although the standard does not mandate the precise spellings needed to distinguish ô 王/おう, ou 追う/おう and oo おお, so it is not completely lossless. (See the hiragana article for more details.)

Nippon-shiki has been established by the International Organization for Standardization in the ISO 3602 strict form. The JSL system, which is intended for use instructing foreign students of Japanese, is also based on Nippon-shiki.