[Nyororin]

I really find it curious that you have learned Hiragana without knowing this...
They are all used together. Katakana is used the least, but Hiragana and Kanji are pretty much shoulder to shoulder in terms of frequency. However, even if it is 50% Hiragana, you`re not going to come close to being able to understand 50% of the information.
To give an example, imagine reading English only understanding those two, three, and four letter words that are used between the more meaningful words. The, is, he, she, that, is, as, this, an, are, etc etc... Those are the type of words that will be written in Hiragana.

So... To put it simply, Kanji is 100% required if you actually plan to read anything written in Japanese.