Guides
The Japanese app localization library
Long-form, opinionated guides for product teams shipping to Japan. Free to read — written by the same people who'd write your copy.
Core guides
Start here. The full-scope guides each cover a major question end-to-end.
3 guides
The Complete Guide to Japanese App Localization (2026)
A working guide to Japanese app localization for mobile teams: register, scripts, screenshots, ASO, and the parts MT still gets wrong. With real before/after copy.
iOS and Android App Localization for Japan: A Step-by-Step Process
An operational walkthrough of localizing an iOS and Android app for Japan: from string extraction to QA, including the gotchas in Xcode and Android Studio.
Japanese App Store Optimization (ASO): The Complete Guide
A practical guide to Japanese ASO: keyword research, app name and subtitle, descriptions, screenshots, and ratings. With examples from real top-ranking apps.
Copy & language
Writing Japanese app copy that reads as native — register, scripts, microcopy, common failure modes.
8 guides
Keigo in Apps: When to Use Polite, Plain, or Casual Japanese
How to choose the right Japanese register (keigo, polite, plain, casual) for your app's brand voice — with concrete examples for fintech, social, and productivity apps.
Why AI Translation Fails for Japanese App Copy (With Examples)
Why DeepL and ChatGPT produce Japanese app copy that natives instantly recognize as foreign — and what fluent rewrites look like, with side-by-side examples.
The 12 Most Common Mistakes in Japanese App Localization
12 specific mistakes that mark an app as foreign-made to Japanese users — punctuation, register, script choice, layout — with real examples and fixes.
Japanese UX Writing: Microcopy That Feels Native
How to write Japanese microcopy for buttons, errors, empty states, and confirmations — with patterns and examples used by top-shelf Japanese consumer apps.
Hiragana, Katakana, or Kanji? Choosing the Right Script for Each UI Element
When to use hiragana, katakana, or kanji in app UI — with a working framework and common mistakes that mark an app as foreign-made.
Japanese Typography and Font Rendering for Mobile Apps
How Japanese type renders on iOS and Android: font fallback, weight selection, line height, and the typography decisions that make a Japanese app feel native.
Mobile UI Conventions Japanese Users Expect
What Japanese mobile users expect that Western apps often skip: information density, navigation patterns, error tolerance, and trust signals — with concrete examples.
How to Make App Copy Sound Native in Japanese (Not Just Correct)
The gap between correct Japanese and natural Japanese — and a working framework for closing it. With seven concrete techniques and side-by-side examples.
Store & growth
ASO, screenshots, store descriptions, custom product pages, and earning reviews in the JP App Store.
7 guides
Designing App Store Screenshots for the Japanese Market
What Japanese App Store screenshots do differently — density, taglines, color, and trust signals. With examples and a working template you can apply.
Japanese ASO Keyword Research: Tools, Methods, and Pitfalls
How to research Japanese App Store keywords without falling into the loanword/kanji trap. Tools, methods, and practical examples for Japan ASO.
Writing App Store Descriptions That Convert in Japan
How to write Japanese App Store descriptions that drive installs: structure, conventions, what to put in the first three lines, and specific phrasing patterns.
Localizing Your App Name and Subtitle for the Japanese App Store
How to choose a Japanese app name and subtitle: when to keep romaji, when to add katakana, and how to write a subtitle that ranks and reads naturally.
How to Earn App Store Reviews from Japanese Users
Why Japanese App Store ratings skew lower, when to ask for reviews, how to respond, and how to recover from low-rating periods. With response templates.
App Preview Videos for Japanese Users
How to design and produce App Store preview videos that work for Japanese users: pacing, captions, music, and what to show in the first three seconds.
Custom Product Pages for Japan: A CPP Strategy
How to use Apple's Custom Product Pages for the Japanese market: which CPPs to build, when to use them, and how they pair with Apple Search Ads.
Engineering
Date and number formats, text expansion, vertical layout, and how to test JP localization before launch.
4 guides
Date, Time, Currency, and Number Formats in Japan
Reference for Japanese date, time, currency, address, and number formatting in mobile apps — with iOS and Android implementation notes.
Handling Japanese Text Expansion and Contraction in Mobile UI
How Japanese text length differs from English in mobile UI: which strings expand, which contract, and how to design layouts that handle both.
Testing Japanese Localization Before Launch
A working QA checklist for Japanese localization: what to test, who should test it, and the specific bugs that only surface in JP-locale builds.
Vertical Text and Layout Considerations in Japanese Apps
When and how to support vertical (tategaki) Japanese text in mobile apps: reading apps, manga apps, and the implementation considerations on iOS and Android.
Market & strategy
Market sizing, push notifications, and paywall copy specific to Japanese conversion patterns.
3 guides
The Japanese Mobile App Market: Size, Trends, and Opportunities
An overview of the Japanese mobile app market: size, monetization, top categories, and what's specific about JP user behavior — for teams considering Japan.
Push Notifications That Work for Japanese Users
How to write and time push notifications for Japanese users: tone, frequency, content, and the patterns that drive opens vs. opt-outs.
Paywall and Subscription Copy for Japanese Conversion
How to write paywall and subscription copy that converts Japanese users — pricing presentation, trust signals, free trial framing, and cancellation transparency.
Skip the DIY
Or have us do it for you.
Productized Japanese app localization by Japanese UX writers & designers. Store listing $500, full app $1,500, ongoing $250/mo.