Gin-chan

No one has replied to this yet? Well, I guess I'll try my best, then. I kind of don't understand the question, though. Maybe that's why nobody has replied. Well, it's essential to learn kana and kanji because they're the characters used in Japanese. And you can't learn the language without being able to read and write kana and kanji. It's like not being able to read or write the alphabet. Without them you won't get anywhere with learning the language, because almost all sentences are written in kana and kanji. So, hiragana is used for original Japanese words, but is also used if the kanji is too difficult to read (like, for children who are still learning kanji). Kanji are the characters derived from Chinese, and katakana is used for foreign words like computer, (コンピュータ), guitar (ギター), that sort of thing. It's also used for onomatopoeia and can be used for emphasis, like using italics in English. I hope this answered your question?