Kanji, Hiragana, and Katakana: Where Did They Come From? How Did They Form Japanese?

It is interesting how Japanese uses three alphabets. I wonder especially how these alphabets originally came about, as it seems somewhat unnatural, at least in my western perspective, to invent new characters for different purposes of the same sounds.

That's a good question, and it goes back to early history of Japanese (and Japan).

Ancient Japanese only communicated with listening and speaking. They didn't have anything for reading or writing. Things started to change in around the 5th century, when Chinese (especially Chinese writing system) was widely introduced to Japan. So Japanese basically had Kanji (literally Chinese characters) first. In this way, Chinese has been leaving deep influence to Japanese since that time. In fact, Sino-Japanese is often considered more formal or literary, just as latinate words in English often mark a higher register.

(Just to notice: Japanese is still an independent language from Chinese. There is no way for anyone to master Japanese with mere Chinese knowledge; vice verse.)

For example, ancient Japanese might use the sound of "yama" to refer to a mountain, but they had nothing to write it down. With the expansion of Chinese culture, they found that "山" also means mountain in Chinese. Therefore, they also used this Chinese character to express the same meaning, but they still read it as how Japanese originally called a mountain. This leads to the Kanji "山" (やま; yama) and one of its sounds. In the meantime, some Japanese also took the sound of Chinese "山" (shān; shan) to Japanese, forming another sound of Kanji "山" (さん; san). Currently, we usually call the readings of Kanji that originated from Chinese as "音読み" (おんよみ; onyomi), and the readings of Kanji that originated from ancient Japanese as "訓読み" (くんよみ; kunyomi).

Kanji may have no/single/multiple onyomi sound(s), and no/single/multiple kunyomi sound(s). Sometimes even native Japanese find it difficult to tell whether a pronunciation of a Kanji is onyomi or kunyomi. So don't worry about it too much. Just learn to use them!

At first, knowing a lot of Kanji was the symbol (as well as some sort of privilege) of a well-educated Japanese. Ancient Japanese books and documents were basically written with Kanji. But it is definitely too complex and is hard for broader usage. The first attempt to form Japanese alphabet was Man'yōgana (万葉仮名). It directly usaed Kanji to mark sounds. However, it was still way too complicated, and one sound may have multiple Kanji options to represent its sound. Then, as the development of Japan's own culture, they started to invent their own characters. Hiragana (平仮名　ひらがな) came out first as a manual simplification of "cursive script", a casual writing style of Chinese characters (i.e., Japanese to some extent, for that time). It was originally used by ladies of the Japanese imperial court for personal communications and literature. Later, Katakana (片仮名　カタカナ) emerged from "regular script", a formal writing style of Chinese characters. It was originally used as a kind of shorthand. Actually, "仮名" itself literally means "borrowed label".

Hiragana and Katakana come from Kanji, yet they are no longer Kanji, and Chinese don't have them either. They are the original invention of Japanese. Both eventually become modern Japanese alphabets and have been helping Japanese become easier for more people to learn and to use.

For example: Chinese character "世" (shì; shi) and Kanji "世" (kunyomi: よ; yo; onyomi #1: せ; se; onyomi #2: せい; sei). Now look at hiragana せ se and katakana セ se. Similar, right? せ and セ both came from simplifying 世, which was also the Man'yōgana of se. Hope this makes you feel more natural when looking at multiple Japanese alphabets.

On the other hand, simulating how Chinese built characters, Japanese also invented a few Kanji that didn't exist in Chinese at first, some of which even came back to modern Chinese, e.g., 腺, 鳕, etc. Some Japanese words that existed in ancient Chinese but with different meanings were also introduced back to modern Chinese with new meanings, e.g., 经济 (ancient Chinese: to let a nation and its people prosper; modern Chinese: economy). Therefore, Japanese writing system originated from Chinese, but these two languages have also been developing together.

Currently, with the development of the world, all cultures spread and influence each other more than anytime in the history. I believe that Chinese, Japanese, English, and even more languages, can (and will) develop and evolve together.

Reference:

1. https://en.wikipedia.org/wiki/Japanese_writing_system
2. https://en.wikipedia.org/wiki/Man%27y%C5%8Dgana
   
3. https://en.wikipedia.org/wiki/Kanji
4. Hmm... my own experiences and knowledge?