Kakuso: Learn Japanese & Kanji

Master Japanese the way it actually sticks: by writing.

Kakuso is a free, complete Japanese learning toolkit. Search a comprehensive dictionary of 200,000+ words and 10,000+ kanji. Practice writing each character by hand with real-time stroke validation. Let a smart spaced repetition algorithm bring everything back at exactly the right moment — so nothing slips away.

Built for serious learners who want to actually master Japanese, not just collect streaks.

★ THE COMPLETE TOOLKIT

- Lightning-fast dictionary — 200,000+ words and 10,000+ kanji. Search anything: readings, meanings, stroke order, component breakdowns, example words. Free, forever, no signup.

- Real handwriting practice — Draw every kanji on a canvas, stroke by stroke, with finger, stylus, or mouse. Real-time stroke validation catches mistakes immediately. Best on tablet with a stylus, but works great on phone.

- FSRS-6 spaced repetition — The most advanced spaced repetition algorithm available. It learns your personal forgetting pattern and surfaces each item right before you'd forget it. No wasted reviews. No re-learning. Nothing evaporates.

- Two tracks, deeper memory — Practice every word two ways: write it from memory, then prove you can read it. Recognition and recall trained separately means lifetime retention.

- Component analysis — Kanji aren't random shapes. They're built from ~200 reusable components. Every dictionary page shows you the building blocks, so you stop memorizing and start understanding.

- Track your progress — Watch your knowledge grow over time across writing and reading. See exactly which items are slipping before you forget them.

★ WHO IT'S FOR

- Complete beginners starting with hiragana and katakana
- Self-taught learners working through JLPT N5 to N1
- People who can read kanji but blank when asked to write them
- Anyone tired of recognition-only flashcard apps
- Adult learners with limited time who need every minute to count
- Tablet and stylus learners
- Learners with dominating kinetic intelligence

If you want gamified streaks and cute mascots, this isn't it. If you want to actually master Japanese in a way that compounds for years, Kakuso is built for you.

★ WHY HANDWRITING + SRS WORKS

Most Japanese apps test recognition: "Do you recognize this kanji?" That's the easy half of memory. The hard half — and the one that matters — is recall: "Can you write it from memory?" These are two different memory pathways in the brain. Training both means you don't just feel like you know Japanese — you actually do.

Combined with FSRS-6 scheduling, every minute of practice works harder. The algorithm tracks which items have peaked and are now fading, then surfaces them at the perfect moment to lock them in for the long term.

★ FREE FOREVER

The core features — dictionary, handwriting practice, spaced repetition — are free, with no signup required. There's an optional premium tier for users who want to support development, but nothing essential is paywalled.

★ BUILT BY A LEARNER, FOR LEARNERS

Kakuso is developed and maintained by Adrian Sieradzki — a motivated learner just like you. It started as a personal tool, born from frustration that no app combined a real Japanese dictionary with real handwriting practice and modern spaced repetition. Today it's available to anyone who wants to learn Japanese the same way — free, forever.

Available in English, Polish, Vietnamese, German, French, Turkish, Spanish, Portuguese, Korean, Thai, and Bahasa Indonesia.

Open it, search a word, click "Add to studies." Tomorrow, the system will ask you to write it from memory. Come back next month — you'll be shocked how much you remember.

Start learning Japanese the way it actually sticks. Free at kaku.so.