21.03 Symbol and Punctuation#

A quick reference for Japanese punctuation, brackets, and frequently used technical symbols. The tables below group related marks so writing drills and reading practice stay consistent across notes.

Brackets & quotation marks#

Symbol	English name	Japanese name	Usage notes
【 】	Lenticular brackets	すみ付き括弧・sumitsuki kakko	Emphasis in headings, subtitles, or to highlight key terms.
「 」	Corner brackets	鉤括弧・kagi kakko	Primary quotation marks for dialogue and citations.
『 』	Double corner brackets	二重鉤括弧・nijū kagi kakko	Nested quotations inside 「 」 passages.
（ ）	Parentheses	丸括弧・maru kakko	Supplemental information, furigana, or clarifications.
［ ］	Square brackets	角括弧・kaku kakko	Academic citations, editorial insertions.
｛ ｝	Curly brackets	波括弧・namikakko	Math notation or grouped list items.

Sentence punctuation#

Symbol	English name	Japanese name	Notes
。	Period	句点・kuten	Ends sentences; no extra space before.
、	Comma	読点・tōten	Separates clauses or items; placed lower than Western commas.
・	Middle dot	中黒・nakaguro	Separates items (e.g., foreign names, list items).
…	Ellipsis	三点リーダー・santen rīdā	Use two consecutive marks (……) in prose for pauses.
―	Em dash	ダッシュ・dasshu	Indicates emphasis or sudden shifts.
ー	Long vowel mark	長音符・chōonpu	Extends vowel sounds in katakana words.
〜	Wave dash	波ダッシュ・namidasshu	Ranges (1〜10), approximate values, or stylistic elongation.
：	Colon	コロン・koron	Ratios, time notation, or explanations.
；	Semicolon	セミコロン・semikoron	Rare; primarily in academic writing.
？	Question mark	疑問符・gimonfu	Optional in casual writing; used regularly online.
！／！	Exclamation mark	感嘆符・kantanfu	Indicates emphasis; avoid stacking more than two.
〽	Alternation mark	庵点・ioriten	Classical poetry to indicate alternating lines.

Mathematical & technical symbols#

Symbol	English name	Japanese name	Usage notes
＋	Plus sign	プラス・加算記号	Addition, positive values.
－	Minus sign	マイナス・減算記号	Subtraction, negative values.
×	Multiplication sign	掛け算記号・kakezan kigō	Multiply scalars; also used for invalid selections.
÷	Division sign	割り算記号・warizan kigō	Division in elementary materials.
＝	Equals sign	等号・tōgō	Equality, assignment in formulas.
≠	Not equal	不等号・futōgō	Inequality; read notto ikōru.
≡	Identical to	恒等記号・kōtō kigō	Identity relations, modular arithmetic.
≒	Approximately equal	約等号・yakutōgō	Statistical rounding or approximations.
±	Plus-minus	プラスマイナス記号	Indicates two possible values.
＜ ／ ＞	Less/greater than	小なり／大なり記号	Inequalities.
≦ ／ ≧	Less/greater than or equal	以下／以上記号	Combine inequality with equality.
｜	Vertical bar	縦線・tatesen	Conditional probability, set notation, separators.
＾	Caret	キャレット	Exponentiation, caret notation.
％	Percent sign	パーセント	Ratios, growth rates.
＄	Dollar sign	ドル記号	Currency.
＃	Hash/number sign	シャープ・井桁	Music sharp, social media tags, note numbers.
＆	Ampersand	アンド	Company names, logical AND (in computing).
＠	At sign	アットマーク	Email addresses, social handles.
_	Underscore	アンダースコア	Filenames, snake_case separators.

Usage reminders#

• Full-width symbols (ＦＷ) maintain alignment in Japanese text. Switch to half-width only when system requirements demand it (e.g., code or URLs).
• Pair quotation marks properly: 「……『……』……」. Avoid mixing Western quotes inside Japanese text unless citing English directly.
• In vertical writing (縦書き), punctuation rotates to match flow; revisit publisher style guides before typesetting.

References#

• JIS X 0213 — Non-kanji character list
• Agency for Cultural Affairs (文化庁) punctuation guidelines for contemporary Japanese writing (Japanese).