一 — One

Meaning

The kanji 一 represents the number one. A single horizontal stroke — nothing else. Its meaning extends beyond the numeral 1 to include the same, each, a single unit, whole, and first.

Visually, 一 is a pure ideograph — the shape is the meaning. Ancient Chinese scribes drew one line to indicate one. Two lines became 二 (two); three became 三 (three). This visual logic is shared across Chinese, Japanese, Korean, and Vietnamese writing traditions.

At just 1 stroke, it has fewer strokes than any other kanji. Japanese schools teach it in Grade 1, and it opens the first lesson of virtually every JLPT N5 course.

Outside arithmetic, 一 shows up throughout Japanese culture. 一期一会 (ichigo ichie, "one time, one meeting") — a Zen-influenced phrase — captures the idea that each encounter is unique and will never repeat exactly. You will find 一 in everyday counting, time expressions, proverbs, and set phrases alike.

Readings

On'yomi (音読み) — Chinese-derived readings

The on'yomi readings come from ancient Chinese pronunciation and appear mainly in compound words (熟語, jukugo).

イチ (ichi) — The most common on'yomi. Used in counting, most compound words, and standalone number contexts.

• 一月いちがつ (ichigatsu) — January (the first month)
• 一番いちばん (ichiban) — number one; the most
• 一度いちど (ichido) — one time, once

イツ (itsu) — The less common reading, found mainly in formal and literary vocabulary. When followed by certain consonants, the final -tsu becomes っ — so 一致 is pronounced いっち (icchi), not いつち.

• 一致いっち (icchi) — agreement, consistency
• 統一とういつ (tōitsu) — unification, unity
• 同一どういつ (dōitsu) — identical, the same

Kun'yomi (訓読み) — Native Japanese readings

Kun'yomi readings are the native Japanese words assigned to this kanji. They appear when the kanji stands alone or combines with native Japanese elements.

**ひと

• (hito-)** — Used as a prefix meaning "one" or "single," typically followed by another word to form a compound.

• 一言ひとこと (hitokoto) — a word; a brief remark

• 一口ひとくち (hitokuchi) — a mouthful; a bite; a sip

• 一休みひとやすみ (hitoyasumi) — a short rest; a break

ひと.つ (hito.tsu) — The native Japanese counter for one object. Part of the indigenous -tsu counting series (ひとつ、ふたつ、みっつ…), used for general objects in casual speech.

• 一つひとつ (hitotsu) — one (object), one piece
• 一つ一つひとつひとつ (hitotsu hitotsu) — one by one, each and every

Common Words & Compounds

The kanji 一 appears in a large number of everyday Japanese words. Below are key compounds grouped by theme.

Numbers & Counting

• 一いち (ichi) — the number one
• 一つひとつ (hitotsu) — one (general counter)
• 第一だいいち (daiichi) — the first; primary
• 一位いちい (ichii) — first place

Time Expressions

• 一日いちにち／ついたち (ichinichi / tsuitachi) — one day / the first of the month
• 一週間いっしゅうかん (isshūkan) — one week
• 一年いちねん (ichinen) — one year
• 一時間いちじかん (ichijikan) — one hour

Quantity & Degree

• 一番いちばん (ichiban) — the most; the best
• 一度いちど (ichido) — once
• 一般いっぱん (ippan) — general; ordinary

Abstract Concepts

• 一致いっち (icchi) — agreement, consensus
• 統一とういつ (tōitsu) — unification
• 一期一会いちごいちえ (ichigo ichie) — once-in-a-lifetime encounter
• 一石二鳥いっせきにちょう (isseki nichō) — killing two birds with one stone

Example Sentences

Related Kanji

• 二 — Two (Kanji N5)
• 気 — Spirit, Energy, Air (Kanji N5)
• 六 — Six (Kanji N5)
• 三 — Three (Kanji N5)
• 十 — Ten (Kanji N5)
• 九 — Nine (Kanji N5)

Memory Tip

One stroke, one meaning. The visual logic is as direct as it gets: draw one line, get 一. If you can write a dash, you already know this kanji. The same character carries the same meaning in Chinese, Korean, and Vietnamese — in Vietnamese it reads NHẤT, as in nhất định (certainly) and thống nhất (unification). Spot a lone horizontal stroke in a Japanese compound and you can always read it as "one."