As anyone reading this probably knows, the concept of kanji first originated from China way back when, and there is a whole other theory on how Chinese characters themselves may have been created, which involves turtle shells, bones, and other mystical things. What I started thinking about, as many others have before, is how some characters that are used in both China and Japan do not necessarily have the same meaning as each other. There are some characters called 国字（こくじ）, meaning characters created in Japan, or also 和製漢字（わせいかんじ）, meaning “characters of Japanese creation”, that do not exist in China. These characters were created by forming existing components into brand new characters, while some characters simply combined multiple preexisting characters into a new character, and then used the meaning associated with the combination. As an example: 込、働、畑、匂、and 峠 are some wasei-kanji that can be frequently seen in Japanese.
I decided to do some digging around to see what differences I could find out between Chinese and Japanese words and characters and their meanings. There are many more differences, but these are some of the highlights I was able to find.
・手紙（てがみ） means “letter” in Japanese, but means “toilet paper” in Chinese. (shǒuzhǐ)
・娘（むすめ）means daughter in Japanese, but means “mother” or “young lady” in Chinese. (niáng)
・勉強 （べんきょう）means “to study” in Japanese, but means “strained” or “reluctance” in Chinese. (miǎnqiǎng)
・高等学校 （こうとうがっこう）means “senior high school” in Japanese, but means “college” in Chinese. (gāoděngxuéxiào)
・大丈夫（だいじょうぶ） means “all right” in Japanese as in “are you all right?”, and means “grown-up man” in Chinese. (dàzhàngfu)
・ 湯（ゆ） means “hot water” in Japanese, and means “soup” in modern Chinese varieties like Mandarin or Cantonese, however Classical Chinese shares the same meaning with Japanese as “hot water”. (tāng)
・下手（へた）means “unskillful” in Japanese, but means “proceed” or “commence” in Chinese. (xiàshǒu)
If there are any other differences that you are aware of, be sure to let us know in the comments!