How did Chinese learn to pronounce Chinese characters?

A simple question hit my mind when I learn Chinese, which is…

How did Chinese learn pronunciation of Chinese characters?

Japanese language contains Chinese character, but on the other hand there are another characters so called “Kata-kana” and “Hira-gana” which is much more pronounce oriented character. By using this, you can learn how to pronounce a character

Example;

国 ＝　Chinese Character (国 means country)
くに　＝　Hira-gana (Pronounce as Kuni)
クニ　＝　Kata-kana (Also pronounce as Kuni)

Then, if you know “Kata-kana” or “Hira-gana”, you can pronounce Chinese characters. The characteristics of “Kata-kana” and “Hira-gana” are much similar to alphabet, rather than Chinese characters.
So Japanese have learned “Kata-kana” and/or “Hira-gana” first, when they are 4 – 7 years old. Then they started to learn Chinese characters.

But on the other hand, as long as I know, Chinese language does not provide such assistant character like “Hira-gana”.
I know that “Pinyin” helps foreigner to learn pronunciation of Chinese.
But I believe that is basically for foreigner not for proper Chinese. Otherwise, Chinese people should learn alphabet first in order to learn pronunciation of their own characters. That is rather weird for me.