Japanese names are written in kanji (Chinese logographic characters with semantic meaning), and pronunciation of kanji is a matter of context. Kanji in names ha

Japanese names are written in kanji (Chinese logographic characters with semantic meaning), and pronunciation of kanji is a matter of context. Kanji in names have a variety of possible common pronunciations, meaning that when given the kanji alone the pronunciation can be ambiguous. The extra two fields are presumably for the kana (syllabary characters that are unambiguously pronounced) spelling of the names. Even then, there are two accepted standards for sorting kana. Japanese is full of these kinds of fun exercises in writing system complexity.