Category romanization

Nippon-shiki

It was invented by physicist Aikitsu Tanakadate (田中館 愛橘) 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 another, similar system, Kunrei-shiki. The difference between Nippon-shiki and Kunrei-shiki is the difference between the kana syllabary and modern pronunciation. In modern standard Japanese, the sounds of the 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 have become identical. For example, the word ''kanadukai'' (Nippon-shiki) かなづかい is pronounced as ''kanazukai'' in the modern Japanese.

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 system of romanization that allows lossless mapping (so-called "round trip" mapping) to and from ''kana''.

Table

	A	I	U	E	O	Yōon
	a	i	u	e	o	rowspan=2 colspan = 3 |
	あ	い	う	え	お
K	ka	ki	ku	ke	ko	kya	kyu	kyo
	か	き	く	け	こ	きゃ	きゅ	きょ
S	sa	si	su	se	so	sya	syu	syo
	さ	し	す	せ	そ	しゃ	しゅ	しょ
T	ta	ti	tu	te	to	tya	tyu	tyo
	た	ち	つ	て	と	ちゃ	ちゅ	ちょ
N	na	ni	nu	ne	no	nya	nyu	nyo
	な	に	ぬ	ね	の	にゃ	にゅ	にょ
H	ha	hi	hu	he	ho	hya	hyu	hyo
	は	ひ	ふ	へ	ほ	ひゃ	ひゅ	ひょ
M	ma	mi	mu	me	mo	mya	myu	myo
	ま	み	む	め	も	みゃ	みゅ	みょ
Y	ya	*	yu	*	yo	rowspan=2 colspan = 3 |
	や		ゆ		よ
R	ra	ri	ru	re	ro	rya	ryu	ryo
	ら	り	る	れ	ろ	りゃ	りゅ	りょ
W	wa	wi		we	wo	rowspan=2 colspan = 3 |
	わ	ゐ		ゑ	を
N	n	rowspan=2 colspan = 7 |
	ん
G	ga	gi	gu	ge	go	gya	gyu	gyo
	が	ぎ	ぐ	げ	ご	ぎゃ	ぎゅ	ぎょ
Z	za	zi	zu	ze	zo	zya	zyu	zyo
	ざ	じ	ず	ぜ	ぞ	じゃ	じゅ	じょ
D	da	di	du	de	do	dya	dyu	dyo
	だ	ぢ	づ	で	ど	ぢゃ	ぢゅ	ぢょ
B	ba	bi	bu	be	bo	bya	byu	byo
	ば	び	ぶ	べ	ぼ	びゃ	びゅ	びょ
P	pa	pi	pu	pe	po	pya	pyu	pyo
	ぱ	ぴ	ぷ	ぺ	ぽ	ぴゃ	ぴゅ	ぴょ