Regex for Japanese

regex-japanese.txt

Regex for matching ALL Japanese common & uncommon Kanji (4e00 – 9fcf) ~ The Big Kahuna!
([一-龯])

Regex for matching Hirgana or Katakana
([ぁ-んァ-ン])

Regex for matching Non-Hirgana or Non-Katakana
([^ぁ-んァ-ン])

Regex for matching Hirgana or Katakana or basic punctuation (、。’)
([ぁ-んァ-ン\w])

Regex for matching Hirgana or Katakana and random other characters
([ぁ-んァ-ン！：／])

Regex for matching Hirgana
([ぁ-ん])

Regex for matching full-width Katakana (zenkaku 全角)
([ァ-ン])

Regex for matching half-width Katakana (hankaku 半角)
([ｧ-ﾝﾞﾟ])

Regex for matching full-width Numbers (zenkaku 全角)
([０-９])

Regex for matching full-width Letters (zenkaku 全角)
([Ａ-ｚ])

Regex for matching Hiragana codespace characters (includes non phonetic characters)
([ぁ-ゞ])

Regex for matching full-width (zenkaku) Katakana codespace characters (includes non phonetic characters)
([ァ-ヶ])

Regex for matching half-width (hankaku) Katakana codespace characters (this is an old character set so the order is inconsistent with the hiragana)
([ｦ-ﾟ])

Regex for matching Japanese Post Codes
/^¥d{3}¥-¥d{4}$/
/^¥d{3}-¥d{4}$|^¥d{3}-¥d{2}$|^¥d{3}$/

Regex for matching Japanese mobile phone numbers (keitai bangou)
/^¥d{3}-¥d{4}-¥d{4}$|^¥d{11}$/
/^0¥d0-¥d{4}-¥d{4}$/

Regex for matching Japanese fixed line phone numbers
/^[0-9-]{6,9}$|^[0-9-]{12}$/
/^¥d{1,4}-¥d{4}$|^¥d{2,5}-¥d{1,4}-¥d{4}$/

This doesn't cover all kanjis. Simple example: 𧓈

To be fair those kanjis are extremely rare and are not used (they would not show up in dictionnaires or rikaichan like extensions) and 99.99% Japanese would not know about them:
https://en.wikipedia.org/wiki/CJK_Unified_Ideographs_Extension_B

Now you can match them with: [𠀀-𪛟]
and to match everything you would simply do: [𠀀-𪛟]|[一-龯]

@cb372, your list comes close to covering all the kana, but a few characters are still missing. You got 「ゞ」 but missed 「ゝ」 and 「ゟ」, and a few others. I believe this would cover all Hiragana and Katakana separately:

Hiragana = [ぁ-ゖ゛-ゟー]
Katakana = [゠-ヿ]

Combined Hiragana & Katakana would be:

Hiragana+Katakana = [ぁ-ゖ゛-ゟ゠-ヿ]

I used the above hiragana+katakana regex to validate the kana portions of the downloadable version of JMDICT and can confirm that apart from a few errors in the JMDICT data, the kana validation works.