[Palapala]

Japanese names are usually written in kanji. Because there are many possible readings for kanji names, including special name-only readings called nanori, furigana are often used to give the readings of names. On Japanese official forms, where the name is to be written, there is always an adjacent column for the name to be written in furigana. Usually katakana is preferred.

http://en.wikipedia.org/wiki/Furigana

Furigana