There are many places where in the old times shells were used as currency. India and China used them during thousands of years and their shell-coins gradually entered the Japanese islands. It is interesting that even nowadays there is a Japanese and Chinese character that means “shell” but if you add strokes to it the meaning changes to “money”.
The Japanese character is 貝(kai) and the simplified Chinese is 贝 (bei / bu). Both are pictographs (They are supposed to look like a shell) and evolvee from and original character that you can see in the next picture:
Picture from Shirakawa.
The character evolved during thousands of years and it became this:
It doesn’t really look like a shell, but if we look at the shape of some money created from shells:
Picture from Shirakawa.
Look at the toothed hole in the middle, it looks like the lines that divide the body of the character 貝.
Picture from Shirakawa.
The character 貝 means “shell”, for example, 二枚貝, a word composed by three kanjis (two, thin things, shell) and it means bivalve, if you change the first character with 1 it becomes 一枚貝 that means univalve… Sometimes I’m amazed with the Japanese language “simplicity”, “intuitiveness” and representative power.
If you add extra strokes to the 貝 it looses the “shell” meaning and acquires the “money/exchange/commerce” meaning. Look at next kanjis where you can easily identify the “shell” part inside them and they all have meanings related with money:
There are many kanjis created from “shell” and they are used to build hundreds of words related with value/money. For the people who is studying Japanese here there is a list of some of the most common words constructed with kanjis with “shell” radical. For Chinese students from this link you have all the derived characters.
貯: savings, store / 貯まる: saving money, 貯金: savings.
財: fortune
販: sells / 販売: to sell, marketing
貨: freight, property
貸: to lend
貿: trade, exchange / 貿易 foreign trade
買: buy
貴: precious, prize
賃: rent, fare, fee / 家賃 rent payment
費: cost, expense
貧: poor, insubstantial / 貧しい : poor 貧乳: insubstantial breasts 🙂
資: data, materials / 資料: data, documents 投資: investment
Other characters I can remind: 貼, 側, 測, 賄, 賂… If you want more info about these words and kanjis I recommend using JDic
