Perfect YourJapanese Writing
Our Chrome extension instantly detects grammar errors, suggests proper formality levels, and helps you write natural Japanese for any situation.
Free during beta — no credit card required
Works everywhere you write
Built for the moments that matter
Whether you're job hunting, studying for JLPT, or navigating daily life in Japan — Kunkun has your back.
Nail your job application
One politeness mistake on an エントリーシート can cost you the interview.
- Catches keigo errors in cover letters and ES
- Flags formality mismatches before they reach a recruiter
- Explains exactly why the phrasing is wrong
Study smarter for JLPT
Practice writing and get instant feedback — N5 through N1.
- Catches tense errors (〜ます vs 〜ました)
- Flags particle mistakes like で vs に
- Learn why each correction is made, not just what
Write to your landlord with confidence
Rental inquiries, neighbor messages, utility forms — formal Japanese matters.
- Catches どうか vs どうぞ and similar keigo slips
- Detects tense and particle errors in formal requests
- Makes your Japanese sound like a native resident
Ready to see the difference Kunkun can make in your Japanese writing?
Get Started FreeType or paste Japanese anywhere — Kunkun checks it as you write and explains every correction.
Grammar Correction
Instantly catch particles, verb conjugations, and structural errors in your Japanese writing.
Formality Adjustments
Choose the right level of formality for emails, business documents, or casual conversations.
Natural Rewriting
Recast a sentence at the politeness level you meant. The Google Docs add-on rewrites a whole selection as casual, polite, or formal.
Powerful features that make your Japanese writing better, faster.
Customize Your Experience
Set your politeness level, writing context, and writer mode. Kunkun adapts to whether you're writing business emails, casual messages, or academic papers.
- Politeness Level
- Casual (だ)Polite (です/ます)Formal (である)
- Writing Context
- BusinessAcademicCasual / Chat
- Writer Mode
- 学習者 — Learner母語話者 — Native Writer
Know What to Work On
Your dashboard names the one pattern you repeat most and explains the rule behind it — then shows whether you're making fewer mistakes per check than the month before.
Kunkun names the pattern you repeat most, with the rule
Mistakes per check, not lifetime totals — so it moves as you improve
The last 30 days set against the 30 before them
Check Several Passages at Once
Paste your writing into one box. Separate passages with a blank line and Kunkun checks each on its own, with its own error count.
- 1 errorPassage 1 · Particle資料は
昨日で送りました→昨日送りました - 1 errorPassage 2 · Politeness会議には
出席できないと思う→出席できないと存じます - 1 errorPassage 3 · Keigo部長がその件について
言いました→おっしゃいました
Works Where You Write
The Chrome extension checks your Japanese in real-time on any website — Gmail, Notion, LinkedIn, and more. The Google Docs add-on gives you a dedicated sidebar for longer documents.
- Dedicated panel
- GmailNotion
- Any text field
- LinkedInTwitter / XRedditChatGPT
- Sidebar add-on
- Google Docs
Have questions?
Installation, browsers, pricing, privacy, and more — answered in our FAQ.
View all FAQsFree during beta. When paid plans launch, beta users get first access and a discount.
Free
During Beta
$0/ mo
- Unlimited grammar checks
- Advanced politeness detection
- Context-aware suggestions
- Google Workspace integration
- JLPT N5–N1 aligned suggestions
- Real-time checking as you type
Start writing better Japanese todayFree during beta
All features included. No credit card needed.
Get Started For FreeQuestions? Contact us