Katakana is another Japanese Alphabet. Katakana is mainly used to translate 'Foreign' words into the Japanese language using Japanese sounds (In this case, with the Katakana Alphabet!) Katakana is also used for onomatopoeia's and to write big scientific words. What is the different between Katakana and Hiragana? Katakana is straight strokes whilst Hiragana is curly. What about Kanji? I think you know that, they are the terrifying Chinese characters. Well have fun studying Japanese!