As far as I konw, there are two parts of Japanese characters.
(1) Old styles (Chinese characters)
Japanese learn Chinese characters 1600 years ago, but they don’t use them usually now. They call it old styles.
However, Japanese is a spell language, the shape of Japanese characters means nothing but the sound.
When they use old styles, they write in Chinese character but spells different.
eg. 桜 spells さくら, sakura.
(2) Hiragana & Katakana
Japanese language is a spell language. they use 50 charactors to stand for 50 different sounds.
eg. あいうえお sounds [a] [i] [u] [e] [o].
eg. かきくけこ sounds [ka] [ki] [ku] [ke] [ko].
Japanese language learned a lot from west country such as America, Franch, British and so on. Many words in Japanese are just the same words in foreign language. They write hiragana to spell their own words, and write katakana to spell foreign words.
But if you speak Janpanese hiragane and katakana sounds just the same. Feeling like this… JMONKEYENGINE & jmonkeyengine.
When I type Japanese words I need IME too. I type “sakura” and the IME recognize it as “さくら” in hiragane style and “サクラ” in katakana style, or maybe “桜” in old Chinese style. I need to choose which is the right word I need.
Here is description of the biggest news website in Japan: