function generateCommandCode and function executeCommandCode define CJK charsets area as follows.

if ( ( $unicodeValueArray[$valueKey] >= 13312 and
       $unicodeValueArray[$valueKey] <= 40863 ) or
    (  $unicodeValueArray[$valueKey] >= 44032 and
       $unicodeValueArray[$valueKey] <= 55203 ) )

13312 to 40863 is Kanji characters area and 44032 to 55203 Hangeul (Korean indigenous) characters area.

Japanese indigenous characters like Hiragana, Katakana are mapped 12289 to 12542 on Unicode.

To process for Japanese correctly, add an area above to the definition.