Localising Your Product for Japan: Beyond Translation
Translating your interface into Japanese is only the first step. Localisation means making the whole product feel as if it were built for Japan: text that fits, forms that accept Japanese names and addresses, familiar ways to pay, and support customers can trust.
Text length and layout
Japanese often takes fewer characters than English to say the same thing, but each character is wider and usually needs a larger font size to stay readable. The result is unpredictable: some strings shrink, others grow. Design for flexibility rather than assuming either.
- Avoid fixed-width buttons and labels. Let them expand, and test with real Japanese text, not placeholder copy.
- Watch line breaks. Japanese has no spaces between words, so text can wrap in awkward places. There are also conventions about which characters shouldn’t begin a line, such as 。 and 、. Check that your platform handles Japanese line breaking well.
- Choose fonts that support Japanese. Missing glyphs can fall back to a different font mid-sentence, which looks broken.
- Don’t build sentences from fragments. Japanese word order differs from English, so joining “You have” + number + “new messages” in code rarely translates well. Give translators whole sentences with placeholders.
Dates, names and addresses
| Item | Common in Japan | What to check |
|---|---|---|
| Dates | Year, month, day: 2026年10月8日 or 2026/10/08 | Use a locale-aware date library. Some official forms also use the Japanese era name, such as 令和 (Reiwa). |
| Times | 24-hour clock is widely used | Show the time zone clearly if users book across countries. |
| Names | Family name first: 山田 太郎 | Label fields “family name” and “given name”, not “first” and “last”. Many Japanese forms also ask for the reading in katakana (フリガナ, furigana). |
| Addresses | From largest to smallest: postal code, prefecture, city, district, block, building | Japanese postal codes have seven digits (〒123-4567). Postcode lookup that fills in the area is common and appreciated. |
| Honorifics | 様 (sama) after a customer’s name | Use the family name with 様 in emails and greetings, never the given name alone. |
The key rule is to avoid assumptions baked into your data model: a single “first name” field, a US-style state list, or validation that rejects Japanese characters will stop customers at the checkout.
Payment and support expectations
Payment habits in Japan differ from many other markets. Alongside credit cards, many customers are used to options such as paying at a convenience store, bank transfer and various mobile or QR-code payment apps. Which methods matter depends on your product and audience, and the landscape changes quickly, so ask your payment provider what is available for Japan and look at what similar Japanese services offer. Show the total amount clearly before checkout, and check current rules on how prices and tax must be displayed with a local adviser.
Support is part of the product. Japanese customers generally expect:
- Help in Japanese, even if it is by email rather than phone.
- A thorough FAQ and clear terms for cancellations, refunds and data handling.
- Prompt, polite replies that acknowledge the problem and give a specific next step.
- Clearly stated business hours, so customers know when to expect an answer.
Finding the right tone
Most Japanese products use polite です・ます (desu/masu) forms in customer-facing text, with short, neutral labels on buttons and menus such as 保存 (hozon, save) or 次へ (tsugi e, next). A playful English voice can sound childish or rude when translated directly, while overly stiff keigo can feel distant. Decide on a tone with your translator and write it down in a short style guide, together with a glossary of product terms, so every screen sounds like the same company.
Working with translators
- Give context. Screenshots, a description of where each string appears and who will read it make a huge difference. “Open” can be a verb or an adjective; the translator can’t tell from a spreadsheet.
- State character limits for labels and notifications.
- Mark what must not be translated, such as brand names, code and placeholders.
- Plan for updates. New features need new strings, so keep the same translator or glossary where you can.
Our Japanese–English translation checklist covers how to prepare files and brief a translator, and our guide to a website for Japanese customers looks at the marketing side.
Test with Japanese users
A translation can be accurate and still feel wrong. Before launch, ask native Japanese speakers to complete real tasks: sign up, enter an address, pay, contact support. Watch where they hesitate. Look for truncated text, odd line breaks, untranslated error messages and emails, and wording that is correct but unnatural. Fix these, then test again after each major update.
Understanding your Japanese users
The best localisation comes from people who understand both your product and Japanese customers. Hanabuddies’ native Japanese team can translate and review interface text, help pages and emails. If your product team works with Japanese partners or users directly, our online lessons with native tutors are conversation-focused and tailored to your work, and your first 15 minutes are free.