Taiwanese kana is a katakana-based writing system once used to write Holo Taiwanese, when Taiwan was ruled by Japan. It functioned as a phonetic guide to hanzi, much like furigana in Japanese or Zhuyin fuhao in Chinese. There were similar systems for other languages in Taiwan as well, including Hakka and Formosan languages.
Unlike Japanese or Ainu, Taiwanese kana are used similarly to the Zhùyīn fúhào characters, with kana serving as initials, vowel medials and consonant finals, marked with tonal marks. A dot below the initial kana represented aspirated consonants, and チ, ツ, サ, セ, ソ, ウ and オ with a superpositional bar represented sounds found only in Taiwanese.