This. Traditional Chinese and Japanese are two seemingly similar but distinctly different things (the latter is forked from the former).

Simplified Chinese is a whole different beast of corruption that is a fork of Traditional Chinese but otherwise not similar to either.

Kanji were also simplified but not necessarily the same way as simplified Chinese. Simplified Chinese also sometimes use 'old' characters.

So sometimes modern Japanese is actually similar to simplified Chinese, sometimes it is similar to traditional Chinese, and sometimes it is unique. There is no simple 'forks'.

For instance, 円 (yen) is simplified Japanese and uniquely Japanese. It used to be same as traditional Chinese 圓. In Chinese it was separately simplified twice to its current form 元. So when you see prices in 円 in Japan and 元 in China it's actually the same original character simplified differently.

Interestingly, traditional Chinese 國 was simplified by reusing an old character and is now 国 both in Japanese and simplified Chinese but not in traditional Chinese.

Why not.

Sometimes Blink is similar to WebKit, sometimes it is similar to KHTML and sometimes it is unique.

I think the fork analogy still holds, no one says forks can't have convergent evolution or cross pollination

To further complicate things, there are the 'kokuji" - characters that were invented in Japan, used only in Japan, and only have Japanese pronunciations - yet are still considered kanji ("Chinese characters)". Examples:

働 "work" 峠 "mountain pass"

https://en.wikipedia.org/wiki/Kanji#Kokuji

I think 'kanji' should be interpreted at large. This is the Chinese writing system and inventing new characters (which happens everywhere this writing system is used) add to the whole corpus of kanji/hanzi even if some are invented or used in specific countries.

峠 has a mandarin pronunciation apparently: https://baike.baidu.com/item/%E5%B3%A0/4336929

働 exists in Chinese too, meaning "labor" 峠 does not exist in Chinese although many Chinese dictionaries (most notably the CC-CEDICT) include it

>峠 "mountain pass"

Incidentially, the backstory behind that kanji is hilarious.

The kanji is composed of the kanjis for "mountain" on the left side, and "up" and "down" on the upper right and lower right sides respectively.

You know what a mountain pass does? Go up and down a mountain.

This is how a lot of kanji are formed. For example 町 (town) is 田 (rice paddy) + 丁 (street). I guess at some point in language formation a lot of towns were primarily collections of rice paddies.