It might be helpful to give a quick overview the differences between Chinese and Japanese – just about everything. The only thing that Japanese and Chinese really share in common is a bunch of words that Japanese borrowed from Chinese and still writes using Chinese characters.

Unlike Chinese which is written purely in Kanji, much of Japanese is written in phonetic characters.  Kanji is the Japanese pronunciation of the Japanese word 漢字, which is a direct borrow from traditional Chinese and means Chinese characters in both languages.

The phonetic characters are the Katakana and the Hiragana. The Katakana look like this:
ア イ ウ エ オ
カ キ ク ケ コ
サ シ ス セ ソ
タ チ ツ テ ト
ナ ニ ヌ ネ ノ
ハ ヒ フ ヘ ホ
マ ミ ム メ モ
ヤ ユ ヨ
ラ リ ル レ ロ
ワ ヰ ヱ ヲ
And the Hirigana look like this:
あ い う え お
か き く け こ
さ し す せ そ
た ち つ て と
な に ぬ ね の
は ひ ふ へ ほ
ま み む め も
や ゆ よ
ら り る れ ろ
わ ゐ ゑ を

The two character sets both cover the same set of sounds. That is, for any Katakana there is a corresponding Hirigana with the same sound.

What does this have to do with Chinese?

Nothing!! But now you know and you should be able to easily tell the difference.  If you learn a lot of Chinese characters, you may be able to guess at the meaning of a lot of things in Japanese when its written with Kanji, but the grammar and pronunciation is entirely different.