Tetsuzukit
Japanese paperwork helper
Only for Mac
Free · In‑App Purchases
Mac
Tetsuzukit stores your identity once and gives it back in whatever format the next Japanese form demands — so you stop retyping your own name, address, and dates from scratch.
Living in Japan means filling the same details into endless forms: the bank wants full-width katakana, the city office wants kanji with furigana, an online form wants romaji, a date wants 和暦 (Reiwa / Heisei). Tetsuzukit keeps one profile and renders every variant on demand.
• Quick Copy panel — press ⌥⌘F anywhere, pick a field, and it's on your clipboard in the exact format you need: full-width / half-width katakana, romaji (family-given or given-family), hyphenated phone, Wareki dates, formatted address.
• Postal code lookup — type a postal code and get the prefecture / city / town, from the full Japan Post KEN_ALL dataset bundled in the app.
• PDF Overlay Helper — open any PDF form, click where each value goes, preview it in place, and export a flattened PDF.
• Privacy first — everything stays on your Mac. Sensitive fields (residence card number, bank account, passport) live in the macOS Keychain, never in the plain profile file. We keep only the last 4 digits of your My Number. No accounts, no servers, no analytics, no tracking.
• You own your data — export and import your profiles as plain JSON any time, free.
FREE
• One full profile with every field and every formatter
• Sensitive fields secured in the Keychain
• Postal code lookup, Quick Copy panel + global hotkey
• PDF Overlay preview and placement
• JSON export / import
PRO (monthly, annual, or one-time lifetime)
• Unlimited profiles — personal, spouse, each child, company, team
• Export flattened PDFs
• Ongoing updates: refreshed postal data and form-format research as Japanese paperwork changes
• All future Pro features included
Tetsuzukit is a personal productivity tool. It does not submit forms to any agency, give legal, immigration, or tax advice, or generate registered seals. It is not affiliated with the Japanese government, Japan Post, or any administrative-scrivener service.
macOS 14 or later. Universal (Apple Silicon + Intel).
SUBSCRIPTION INFORMATION
Tetsuzukit Pro is available as a 1-month or 1-year auto-renewable subscription (both with a 14-day free trial), or as a one-time Lifetime purchase. Payment is charged to your Apple ID account at confirmation of purchase. Subscriptions renew automatically unless auto-renew is turned off at least 24 hours before the end of the current period; your account is charged for renewal within 24 hours before the period ends. Manage or cancel anytime in your App Store account settings after purchase. Any unused portion of the free trial is forfeited when you purchase a subscription.
Terms of Use (EULA): https://jasonyeyuhe.github.io/tetsuzukit/terms/
Privacy Policy: https://jasonyeyuhe.github.io/tetsuzukit/privacy/
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
New — Procedures Guide: a browsable, trilingual reference for 17 common procedures (residence, city hall, insurance & pension, tax, banking, family, driving) with steps, a document checklist, and official links. Reference only — not legal advice.
The developer, Yuhe Ye, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Yuhe Ye
- Size
- 5 MB
- Category
- Productivity
- Compatibility
Requires macOS 14.0 or later.
- Mac
Requires macOS 14.0 or later.
- Mac
- Languages
English and 2 more
- English, Japanese, Simplified Chinese
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Tetsuzukit Pro Monthly $0.99
- Tetsuzukit Pro Annual $9.99
- Tetsuzukit Pro Lifetime $9.99
- Copyright
- © 2026 Jason Ye