Built for serious Japanese learners

Kotrin is an AI-powered app designed specifically for Japanese learning. Kotrin covers all aspects of language practice—speaking, reading, listening, and writing—with real-time, personalized lessons. Kotrin curates learning contents that adapts to your interests, learning style, and current level, making your learning journey faster and more effective.

Kotrin uses advanced AI technology to create a personalized learning experience just for you. When you start, Kotrin creates your language profile based on your current Japanese skills using our unique 1536-dimensional profiling system. This creates your personal language fingerprint. As you learn, our AI continuously adapts your lessons—adjusting difficulty, content focus, and practice scenarios based on your progress. Think of it as having a personal tutor who knows exactly what you need to learn next.

Yes! Kotrin has a free plan with selected lessons, personalized learning, and practice with quizzes, vocabulary, and more. Pro unlocks the full lesson library, unlimited practice across features, and more advanced conversation practice. Start free and upgrade whenever you're ready.

Kotrin is perfect for Japanese learners at any stage. Beginners can build a solid foundation quickly with our adaptive approach. Intermediate learners can tackle complex grammar and cultural nuances with personalized content. Advanced speakers can refine their fluency with authentic scenarios. We also welcome teachers who want to create engaging classroom lessons quickly while providing personalized content for their students.

Yes! Research shows that personalized lesson content improves learning effectiveness by 40% compared to traditional one-size-fits-all approaches. Our tailored method builds both your communication skills and grammatical accuracy, creating a well-rounded and enjoyable learning experience that actually works.

Kotrin uses our advanced AI system to create your unique language fingerprint across 1536 different dimensions. This goes far beyond simple beginner/intermediate/advanced levels. We assess your reading, writing, speaking, and listening skills in detail, then create a personalized learning path that adapts to your specific strengths and areas for improvement.

Kotrin takes a completely different approach to language learning. Instead of static, pre-made lessons, we dynamically curate learning content and our AI tutor generates responses based on your interests, level, and learning style. Our unique profiling system maps your Japanese skills across 1,536 dimensions—much more detailed than traditional apps. This creates your personal language fingerprint, enabling precise personalization and a faster path to fluency.

We believe in doing one thing exceptionally well, which is why we focus exclusively on Japanese. By dedicating ourselves to Japanese, we can create learning materials that go beyond what AI alone can generate. Japanese's beautiful complexity, flexibility, and rich cultural heritage make it a fascinating language to master, and we want to help you discover all its nuances.

Currently, Kotrin is available only in English. Other languages such as Chinese, Korean, Vietnamese, Indonesian, Arabic, Farsi, Burmese, and Nepali will be added in early 2026.

Yes, you can manage your subscription directly within the Kotrin app. You can upgrade or downgrade your plan at any time through the app's settings.

Pro plans are billed monthly. You can cancel anytime through the app, and you'll continue to have access to Pro features until the end of your current billing cycle.

No hidden fees. The price you see is the price you pay. All taxes are included in the displayed price.