japanese can have many homophones for one pronunciation, e.g. "kami" can mean “god”, “hair”, "paper", or "upper stream". since each words is made of the same syllables, they are written using the same kana (かみ in hiragana and カミ in katakana), but since they all have very different meanings, the kanji character for each word is quite different. the kanji for "god" is 神, the kanji for "hair" is 髪, the kanji for "paper" is 紙, and the kanji for "upper stream" is 上. however, each kanji character can have several different pronunciations, according to which meaning (which “reading”) is intended.