Japanese Braille is the braille script of the Japanese language. It is based on the original braille script, though the connection is tenuous. In Japanese it is known as , literally "dot characters". It transcribes Japanese more or less as it would be written in the hiragana or katakana syllabaries, without any provision for writing kanji.
Japanese Braille is a vowel-based abugida. That is, the glyphs are syllabic, but unlike kana they contain separate symbols for consonant and vowel, and the vowel takes primacy. The vowels are written in the upper left corner (dots 1, 2, 4) and may be used alone. The consonants are written in the lower right corner (dots 3, 5, 6) and cannot occur alone. However, the semivowel y is indicated by dot 4, one of the vowel dots, and the vowel combination is dropped to the bottom of the cell. When this dot is written in isolation, it indicates that the following syllable has a medial y, as in mya. Syllables beginning with w are indicated by dropping the vowel dots to the bottom of the cell without additional consonant dots.
In Japanese Braille, bare vowels are assigned to braille patterns that occupy the upper-left half of the cell (dots 1âÂÂ2âÂÂ4): . While the first three vowels are the same as the numerals 1, 2, and 3, this pattern does not continue, and the cells representing other kana have no apparent connection to international values or numerical order. Common punctuation marks tend to follow standard international values, with several doing double-duty with the w- series of kana braille. Beyond the bare vowels, all other kana use the vowel series, called dan, with each gyà  (consonant series) represented either by adding specific dots, lowering the dot positions of the dan vowel patterns within the cell, or both.
The patterns for adding yà Âon to a mora can be added to the modifiers for dakuten and handakuten as a compound kana modifier, and the ya gyà  braille series is based on the yà Âon dot pattern. The symbol for syllabic "n" is based on its historical derivation from mu.
In kana, a small tsu (), called sokuon, is used to indicate that the following consonant is geminate, and in interjections as a glottal stop. In katakana only, a long vowel is indicated with a horizontal stroke () called a chà Âon. This also looks like a half dash in braille:
The placement of these blocks mirrors the equivalent kana: the sokuon indicates that the following consonant is geminate, whereas the chà Âon indicates that the preceding vowel is long.
In kana, the voiced consonants g, z, d, b are derived from the voiceless consonants k, s, t, h by adding a diacritic called dakuten to the kana, as in gi; in foreign words, vu is written by adding this to the vowel u. Similarly, p is derived from h by adding a small circle, handakuten. Two kana are fused into a single syllable by writing the second small, as in kya from ki + ya; this is called yà Âon.
In Japanese Braille, the signs for these are prefixes. That is, the order is dakuten + ki for gi. When more than one occurs in a single syllable, they are combined in a single prefix block, as the yà Âon-dakuten used for gya.
The yà Âon prefix uses the dot that represents y in the blocks ya, yu, yo. When placed before ka, ku, ko, it produces kya, kyu, kyo. Likewise, the yà Âon-dakuten prefix before ka, ku, ko creates gya, gyu, gyo. And so on for the other consonants.
Unlike kana, which uses a subscript e, in braille the -ye in foreign borrowings is written with yà Âon and the kana from the e row: that is, kye, she, che, nye, hye, mye, rye, voiced gye, je, bye, and plosive pye are written with the yà Âon prefixes plus ke, se, te, ne, he, me, re. The syllable ye is written yà Âon plus e.
There is also a prefix for medial -w- called gà Âyà Âon. When combined with ka, it produces the obsolete syllable kwa. It may also be fused with the voicing prefix for gwa. For foreign borrowings, this extends to kwi, kwe, kwo and gwa, gwi, gwe, gwo. Gà Âyà Âon may also be combined with the vowels i, e, o for foreign wi, we, wo (now that the w in the original Japanese kana for wi, we, wo is silent); with ha, hi, he, ho for fa, fi, fe, fo and (when voiced) for va, vi, ve, vo; and with ta, chi, te, to for tsa, tsi, tse, tso. These two prefixes are identical to the question mark and full stop.
These all parallel usage in kana. However, there are additional conventions which are unique to braille. Yà Âon and yà Âon-dakuten are also added to chi and shi to write ti, di and si, zi found in foreign borrowings; similarly gà Âyà Âon and gà Âyà Âon-dakuten are added to tsu to write tu, du. This differs from the system used in kana, where the base syllables are te and to respectively, and a subscript vowel i or u is added.
In an assignment that is counter-intuitive in kana, yà Âon + handakuten is prefixed to tsu, yu, yo to produce tyu, fyu, fyo in foreign words, and voiced for dyu, vyu, vyo. The latterâÂÂyà Âon + dakuten + handakuten, is impossible in kana:
Japanese Braille is written as print Japanese would be written in kana. However, there are three discrepancies:
Besides the punctuation of Japanese, braille also has symbols to indicate that the following characters are digits or the Latin alphabet.
As noted above, the space is used between words and also where an interpunct would be used when names are written in katakana. There are several additional punctuation marks.
Western letters and digits are indicated as follows:
An additional sign indicates that the following characters are specifically English words and not just in the Latin alphabet.
Words immediately follow numbers, unless they begin with a vowel or with r-. Because the syllables a i u e o and ra ri ru re ro are homographic with the digits 0âÂÂ9, a hyphen is inserted to separate them. Thus "six people" (6 nin) is written without a hyphen, , but "six yen" (6 en) is written with a hyphen, , because would be read as .
There are both a six dot system, tenkanji, the significantly more common writing system which phonetically transcribes kanji, and an eight-dot extension of Japanese Braille, kantenji, which is less commonly used and aims to preserve the meaning of Japanese kanji by depicting the radicals. Tenkanji is also more similar to how Chinese Brailles are transcribed.