Furigana (ふりがな), also called yomigana, are kana printed next to a kanji or other character to indicate its pronunciation. In horizontal text, they are above the character; in vertical text, they are to the right of the character. They are one type of ruby text.

Furigana may be added by character, in which case the part of a word which corresponds to a kanji is centered over that kanji; or by word or phrase, in which case the entire word is centered over its characters, even if the kanji do not represent equal shares of the kana needed to write them. The latter method is more common, especially since some words in Japanese have unique pronunciations that are not related to any of the characters the word is written with.

When it is necessary to distinguish between Japanese- and Chinese-derived pronunciations, Japanese pronunciations are written in hiragana, and Chinese pronunciations are written in katakana. However, this distinction is really only important in dictionaries and other reference works, and in prose hiragana is typically used regardless of the origin of the pronunciation.

Recently, writers have experimented with unusual uses of furigana. In manga, some writers will use furigana to represent slang pronunciations, which would become hard to understand without the kanji to provide their meaning. Another use is to write the kanji for something which had been previously referenced, but write furigana for "sore" or "are", meaning "that", indicating that the characters simply refer to it with a pronoun, but clarifying for the reader what thing was meant.

Also, because the kanji represent meaning while the furigana represent sound, one can combine the two to create puns or indicate meanings of foreign words. One might write the kanji for "blue", but use katakana to write the pronunciation of the English word "blue", thus giving using an English word while providing its meaning. The Japanese translations of Harry Potter use this to translate puns while retaining their meaning, and to translate some words like "Firebolt" which are proper nouns, but whose meaning should not be disregarded.

In a similar vein, some Westerners choose kanji for their names, and use furigana to clarify the pronunciations. This has a particularly neat effect when the kanji are chosen not for their phonetic value but for their meaning, allowing one to translate the meaning of one's name while retaining the original pronunciation.

Yet another use is to provide English text and use furigana to indicate the pronunciation of each word. Another even more esoteric use is to write English text, and in furigana write Japanese words, even in kanji, that correspond to the meaning of the English, effectively translating it in place. While rare now, some late 19th - early 20th century authors used kanji as furigana for loanwords written in katakana.

In the written style known as kambun, which is the Japanese approximation of Classical Chinese, small marks called kunten were sometimes added as reading aids. Unlike furigana, which indicate pronunciation, kunten indicated Japanese grammatical structures absent from the kambun, as well as showing how words should be reordered to fit Japanese sentence structure.