一

Meaning in English

one, number one

Stroke order

Animated kanji stroke order

一

Sentence

Related sentences

N3 彼は一度も休むことなく三時間働き続けた Kare wa ichido mo yasumu koto naku sanjikan hataraki tsuzuketa He worked three hours without resting once N4 私は一度富士山に登ったことがあります。 Watashi wa ichido Fujisan ni nobotta koto ga arimasu. I have climbed Mt. Fuji once. N4 もう一度説明させてください。 Mou ichido setsumei sasete kudasai. Please let me explain once more. N4 もう一度説明してもらえますか。 Mou ichido setsumei shite moraemasu ka. Could you explain one more time? N4 早く終われば一緒に行こう Hayaku owareba issho ni ikou If it finishes early let us go together N4 この問題は一人で考えるより誰かと話したほうが分かりやすいよ Kono mondai wa hitori de kangaeru yori dareka to hanashita hou ga wakariyasui yo This problem is easier if discussed with someone than alone N4 先生に直してもらった文章をもう一度読み直した Sensei ni naoshite moratta bunshou o mou ichido yominaoshita I reread the text corrected by the teacher N5 一緒に行きましょう。 Issho ni ikimashou. Let’s go together. N5 もう一度言ってください。 Mou ichido itte kudasai. Please say it again.

Dictionary

Word context

What it means

一 (ichi) means 'one' and denotes the basic numerical quantity 1 as well as the abstract idea of singularity or unity; it functions as a standalone numeral, a morpheme in compound words to mark primary/first status, and as the written digit '1' in modern contexts.

Main meanings

First or primary status when used in compounds or rankings (an ordinal/priority sense distinct from mere counting).
Unity or whole, used metaphorically to mean 'as one' or 'single entity'.
In mathematics and algebra the multiplicative identity (the concept of 1 as leaving values unchanged).
As a neutral written digit representing the numeral 1 in dates, serials and numeric data.

How to use it

Found across spoken and written Japanese: as a digit in numbers and dates, as ichi in Sino-Japanese compounds to mark order or rank, and as hitotsu in native counting; usable in both formal and casual contexts depending on reading and construction, and frequently appears in set phrases and ordinal expressions.

Variants and close terms

一つ (hitotsu) - one (native counter for general objects)
一番 (ichiban) - the best/first (superlative/ordinal)
壱 (ichi) - formal/financial variant used in legal or monetary contexts
二 (ni) - two (antonym)

Composition

An atomic kanji composed of a single horizontal stroke representing a single unit; it serves as its own radical, has stroke count one, and does not decompose into smaller semantic components—its shape directly encodes the concept of 'one'.

Etymology

一: the Sino-Japanese On'yomi ichi reflects an Old/Middle Chinese borrowing (phonetic lineage from *yit), while the native Kunyomi hito(tsu) preserves Japan's indigenous counting vocabulary; the two readings coexist because of historical borrowing and adaptation.

Origin

The character entered Japan with Chinese writing around the 5th–6th centuries CE and became one of the earliest and most essential characters used for counting, taxation, calendrical records and administration; its simple single-stroke form made it widely adopted in education and bureaucracy from ancient times onward.

Word class

numeral (数詞)

Word

Related words by kanji and components

N4 一度 ichido once, one time N4 一杯 ippai full, one cup, a lot N4 一生懸命 isshoukenmei with utmost effort, very hard, earnestly N5 一緒に issho ni together N5 一時間 ichijikan one hour N5 一匹 ippiki one small animal N5 一昨日 ototoi day before yesterday N5 一日 ichinichi one day, whole day N5 一番 ichiban first, best, most

Kanji