Why the kanji for buy has a shell in it (買)

The kanji for buy, 買 (kau), has a shell at the bottom: 貝 (kai), a cowrie. In ancient China, cowrie shells were used as money, so 貝 turns up in kanji about wealth and trade, like 財, wealth, and 貯, savings. On top of 買 sits 罒, a net: a net and some money, and you’re shopping.

What the kanji say

貝 (kai) began as a drawing of a cowrie shell, the small, glossy shell once used as money. In Japanese today it means shellfish in general: 貝殻 (kaigara) is a seashell. The Japanese word for a cowrie is 宝貝 (takaragai), literally “treasure shell”.

罒, on top of 買, is a squashed form of 网, a net.

買 (kau, bai) means to buy: 買う (kau) is the verb, and 買い物 (kaimono) is shopping.

財 (zai) is wealth or property. The shell gives the meaning, and 才, on the right, gives the sound. It’s the first kanji of 財布 (saifu), a wallet.

貯 (cho) means to store up or save. The shell gives the meaning again, and 宁, on the right, gives the sound; it began as a drawing of a container for storing things. 貯金 (chokin) is savings, and 貯める (tameru) is to save up.

Where it really comes from

This time the video’s history holds up. The Shuowen Jiezi, a Chinese dictionary from around 100 CE, records that in early times shells were used as money and turtle shells were treasured, that coins appeared under the Zhou dynasty, and that the Qin dynasty abolished shell money and used coins instead. Kanji about money kept their shells long after the shells stopped being money.

For 買 itself, the Shuowen just says it means to trade and is made of 网 and 貝. How the net and the shells fit together isn’t certain. The video pictures a net scooping up shells; another reading is money coming out of a net bag. Either way, a net and money add up to buying.

Selling has a story of its own. The old form of 売 (uru), to sell, was 賣: 出, to go out, on top of 買. Selling was goods going out. When Japanese simplified 賣 into 売, the shell disappeared.

Many other money kanji still have one: 費 in 費用 (hiyou), cost, 貸 in 貸す (kasu), to lend, 賃 in 賃金 (chingin), wages, and 貧 in 貧しい (mazushii), poor.

How to use it

• コンビニで水を買いました。

  Konbini de mizu o kaimashita.

  I bought some water at a convenience store.

• 何を買ったの？

  Nani o katta no?

  What did you buy?

• 財布を忘れた！

  Saifu o wasureta!

  I've forgotten my wallet!

• 毎月少しずつ貯金しています。

  Maitsuki sukoshi zutsu chokin shite imasu.

  I save a little every month.

• 買い物に行ってきます。

  Kaimono ni itte kimasu.

  I'm off to do some shopping.

• 買う and 飼う are both kau. 買う is to buy, and 飼う is to keep an animal: 猫を飼う (neko o kau) is to have a cat. In speech, the context tells you which one is meant.
• On a shop sign, お買い得 (okaidoku) means a bargain, a good buy.
• 売る (uru) is to sell, and 売買 (baibai) is buying and selling, with 売 first.
• 衝動買い (shoudougai) is impulse buying, the shopping you didn’t plan.

Words with the same kanji

Remember it

A net (罒) full of shells (貝): that’s shopping, ancient China style. Keep your shells in a 財布, and put the rest away as 貯金.

The kanji in this lesson

Tap Draw it to watch the stroke order. Numbers show where each stroke starts.

Draw it

Draw it

Draw it

Draw it

Sources

• Dong Chinese: 貝
• Dong Chinese: 買
• Dong Chinese: 賣 (old form of 売)

Written by the Chirami team with the help of AI, then checked against JMdict and KANJIDIC2. How we write lessons. Spotted a mistake? Email support@brightsmilesolutions.org.