They're just called kanji. And I know I'm just a silly gaijin, but I can't for the life of me find the usefulness in them. Each kanji has about three or four different interpretations, as a word, as its Chinese root, as its Japanese root, and as the individual sound it creates when used in a word. And the sound it creates is almost always easier to write in hiragana or katakana. You can use a three-stroke hiragana symbol or use a 15-stroke kanji symbol that can be interpreted the same way. Aaah, it's crazy!