The core idea: numbers a pen cannot change
Look at the plain numerals as shapes rather than meanings. 一 is one horizontal line. Add a short line above it and you have 二; add one more and you have 三. Put a vertical stroke through 一 and it becomes 十, and a small slanting stroke on top of 十 turns it into 千. On a gift envelope or a receipt, a single dishonest stroke could multiply a sum by three or by a hundred.
Daiji (大字), literally big characters, solve this by replacing exactly those vulnerable numerals with complex shapes that do not grow into anything else. That is why the four you really need are 壱, 弐, 参 and 拾, the stand-ins for 一, 二, 三 and 十. Numerals such as 四, 五 and 八 cannot be turned into other numbers so easily, so everyday writing rarely bothers to replace them.
| Japanese | Romaji | Meaning |
|---|---|---|
| 一は線を足すと二や三になります。 | Ichi wa sen o tasu to ni ya san ni narimasu. | Add a line to one and it becomes two or three. |
| 十に一画足すと千になります。 | Jū ni ikkaku tasu to sen ni narimasu. | Add one stroke to ten and it becomes a thousand. |
| だから、お金の額は大字で書きます。 | Dakara, okane no gaku wa daiji de kakimasu. | That is why sums of money are written in daiji. |
The daiji you will actually meet
Traditional lists give a daiji for every numeral, but daily life uses only a handful. The first four rows are the core set, and also the characters that Japanese rules for certain official records still name. The rest are rare enough that many Japanese adults would need a moment to read them.
| Daiji | Reading | Plain form | How often you will see it |
|---|---|---|---|
| 壱 | ichi | 一 | Common: envelopes, receipts, the 10,000 yen note |
| 弐 | ni | 二 | Common: documents, the 2,000 yen note |
| 参 | san | 三 | Common: envelopes, especially 30,000 yen |
| 拾 | jū | 十 | Common: documents and envelopes, as in 弐拾 |
| 萬 | man | 万 | Common on envelopes: the old form of 万, used for dignity |
| 伍 and 阡 | go and sen | 五 and 千 | Occasional: envelopes, to match the style |
| 佰, 肆, 陸, 漆, 捌, 玖 | hyaku, shi, roku, shichi, hachi, kyū | 百, 四, 六, 七, 八, 九 | Rare: dictionaries, old documents |
One honest note: 萬, 伍 and 阡 do not really defend anything, because 万, 五 and 千 are hard to forge. People use them because a line of daiji looks formal and consistent. That is style, not security.
Where you meet them: banknotes, festival boards and shop names
The first daiji most people in Japan see are in their wallets. The 10,000 yen note says 壱万円 in kanji, and the rarely seen 2,000 yen note says 弐千円. Neighbourhood festivals post boards listing donors and their gifts, such as 金壱萬円 followed by a family name, and shrine stones and old signs use daiji in dates and sums. Shop names and fiction borrow 壱, 弐 and 参 for an old-fashioned flavour.
A learner has just noticed the kanji on a banknote and asks a Japanese friend about it over coffee.
| Japanese | Romaji | Meaning |
|---|---|---|
| この字は何と読むんですか。 | Kono ji wa nan to yomu n desu ka. | How do you read this character? |
| 「いち」です。一の難しい書き方ですよ。 | Ichi desu. Ichi no muzukashii kakikata desu yo. | It's ichi. It's the complicated way of writing one. |
| 一万円札には壱万円と書いてあります。 | Ichiman-en satsu ni wa ichiman-en to kaite arimasu. | The ten-thousand-yen note has ichiman-en written in formal characters. |
| 二千円札は最近あまり見ませんね。 | Nisen-en satsu wa saikin amari mimasen ne. | You hardly see two-thousand-yen notes these days. |
| お祭りでは、寄付した人の名前と金額が張り出されます。 | O-matsuri de wa, kifu shita hito no namae to kingaku ga haridasaremasu. | At festivals, donors' names and amounts are posted up. |
Writing the amount on a money envelope
Gift money for weddings, called goshūgi, and condolence money for funerals, called kōden (香典), is given in a special envelope with two layers. The outer wrapping, uwazutsumi, literally the upper wrapping, carries the purpose and your name. Inside is the nakabukuro (中袋), literally the inner bag, which holds the notes. The amount goes in the centre of its front, written vertically: 金, then the number in daiji, then 円, with 也 optional. Your address and name go on the back, in the lower left.
Usual amounts depend on your relationship, age and region, so ask a colleague. Two habits are widespread: odd amounts such as 30,000 yen are preferred for weddings, and sums containing four or nine, whose readings shi and ku can suggest death and suffering, are avoided.
| Japanese | Romaji | Meaning |
|---|---|---|
| 中袋に金額を書くんですよね。 | Nakabukuro ni kingaku o kaku n desu yo ne. | I write the amount on the inner envelope, right? |
| 三万円なら、金参萬円と書きます。 | Sanman-en nara, kin sanman-en to kakimasu. | For thirty thousand yen, you write kin sanman-en. |
| 裏に住所と名前を書いてください。 | Ura ni jūsho to namae o kaite kudasai. | Write your address and name on the back. |
| 筆ペンで書いたほうがいいですよ。 | Fude-pen de kaita hō ga ii desu yo. | It's better to use a brush pen. |
| 金額の欄が印刷されていたら、そこに書けば大丈夫です。 | Kingaku no ran ga insatsu sarete itara, soko ni kakeba daijōbu desu. | If there's a printed box for the amount, just write it there. |
| すみません、ご祝儀袋はどこですか。 | Sumimasen, goshūgi-bukuro wa doko desu ka. | Excuse me, where are the wedding gift envelopes? |
| 香典袋も置いてありますか。 | Kōden-bukuro mo oite arimasu ka. | Do you also stock condolence envelopes? |
Kin and nari: the words that fence in the number
Daiji protect the digits; two small words protect the ends. Kin (金), literally gold, opens the sum so nothing can be squeezed in front. Nari (也), an old word meaning it is, closes it. Nari once showed that no smaller unit such as sen followed the yen. Today it is optional.
The same logic appears on a handwritten receipt, ryōshūsho, where the sum is often written ¥10,000- with a dash, or followed by a mark such as ※, so that no digit can be added at the end. Below the sum comes the tadashigaki, literally the proviso writing, saying what the money was for. A shop assistant is writing one by hand.
| Japanese | Romaji | Meaning |
|---|---|---|
| 金壱萬円也。 | Kin ichiman-en nari. | The sum of ten thousand yen. |
| 領収書をお願いできますか。 | Ryōshūsho o onegai dekimasu ka. | Could I have a receipt, please? |
| 宛名は会社名でお願いします。 | Atena wa kaishamei de onegai shimasu. | Please make it out to the company. |
| 但し書きはいかがなさいますか。 | Tadashigaki wa ikaga nasaimasu ka. | What should I put as the description? |
| 但し、お品代として。 | Tadashi, o-shinadai to shite. | Being payment for goods. |
| 上記正に領収いたしました。 | Jōki masa ni ryōshū itashimashita. | Received the above sum in full. |
Beyond the basics: official documents, cheques and old forms
The strictest home of daiji is official paperwork in vertical kanji. Regulations for some registers name exactly 壱, 弐, 参 and 拾, which confirms the organising idea: the rules protect the four numerals that can be forged, and nothing else. Most modern forms are horizontal and use Arabic numerals, though, so you may never write a daiji on one. Cheques, which few individuals use, follow the same principle. Choosing between kanji and Arabic numerals in ordinary documents has its own guide, and New Year cards, also covered separately, normally write dates in plain kanji rather than daiji.
Combinations work just like ordinary kanji numbers. 弐拾 is nijū, twenty; 参拾萬 is sanjūman, three hundred thousand; 拾壱 is jūichi, eleven. On shrine stones and older documents you will also meet the traditional forms 壹, 貳 and 參, which are simply older shapes of the same daiji.
| Japanese | Romaji | Meaning |
|---|---|---|
| この字は壱の古い形です。 | Kono ji wa ichi no furui katachi desu. | This character is an older form of the formal one. |
- 弐拾萬円: nijūman-en, 200,000 yen
- 参拾萬円: sanjūman-en, 300,000 yen
- 伍阡円: gosen-en, 5,000 yen
- 壹, 貳, 參: older forms of 壱, 弐, 参
Lookalikes and double lives: daiji outside numbers
Two daiji have near-twins that learners confuse. 壱 and 売 (uru, to sell) share the same top and differ only at the bottom: 壱 ends in a small hooked 匕, 売 in two legs. 弐 and 式 (shiki, ceremony) share the same frame; 弐 has 二 inside it, 式 has 工. Read the inner part and you will never mix them up.
Two others lead double lives as ordinary kanji. 参 is also the san of sanka suru, to take part, and the humble verb mairu, to come or go. 拾 is the everyday verb hirou, to pick up, borrowed for ten because in Chinese the two sounded alike. Seeing them in words is good practice for reading them in sums.
| Japanese | Romaji | Meaning |
|---|---|---|
| 明日、そちらに参ります。 | Ashita, sochira ni mairimasu. | I will come to your office tomorrow. |
| 駅で財布を拾いました。 | Eki de saifu o hiroimashita. | I found a wallet at the station. |
| 入学式は来週です。 | Nyūgakushiki wa raishū desu. | The entrance ceremony is next week. |
| 切符売り場はどこですか。 | Kippu uriba wa doko desu ka. | Where is the ticket office? |
Common mistakes when writing daiji
Writing 参拾萬 for thirty thousand is the most expensive error, because 参拾萬 is three hundred thousand. The cause is English: thirty thousand sounds like thirty plus thousand. Japanese counts in man, so thirty thousand is three man, 参萬. Convert to man first, then write.
Converting every digit, including 四 into 肆, comes from treating daiji as a complete alternative set. Their purpose is to protect the forgeable numerals, so 壱, 弐, 参, 拾 and the conventional 萬 are all an envelope needs.
Writing 金30,000円 down a vertical envelope comes from habit with price tags. Vertical lines take kanji. The exception is a printed horizontal box, which is designed for Arabic numerals.
Giving 壱 or 弐 a special pronunciation comes from assuming a new shape means a new word. Daiji are read ichi and ni like the plain forms.
Choosing 40,000 or 90,000 yen for a gift comes from thinking in round numbers. Those amounts are widely avoided because of shi and ku. Ask a colleague what is usual before you write anything.