Japanese that actually clicks.
Kotsu turns kana, radicals, kanji, and useful words into one serious little study system, built for quick sessions before Japan and the long game after.
Make category clears feel earned.
No awards yet — finish a category and Kotsu should hand you one.
The first clear is the point: progress should feel ceremonial, not invisible.
Hiragana Bloom
ひらがな開花
Cleared every hiragana shape, branch, and double so the base sound map is yours.
Katakana Circuit
カタカナ回路
Finished the borrowed-sound set and locked in the sharp mirror script.
Radical Forge
部首鍛錬
Mastered the building blocks that make later kanji feel less mysterious.
Course Tree
A trunk for required order, branches for the nearby ideas that still belong to mastery.
Pieces become meaning.
Structured kana rows with voiced sounds, contractions, and doubles grouped into one clear path.
A mirror course for borrowed sounds so learners can compare shape, sound, and usage side by side.
Semantic building blocks taught as reusable parts, not isolated trivia.
Starter kanji ordered to feel reachable, with readings and meaning attached early.
Short everyday words and greetings that make the symbols feel immediately useful.
5-minute warm-up
Run one sound unit, then one matching katakana branch while the contrast is still fresh.
start sprint 組み立てRadical recipe loop
Spot a radical, recall the meaning, then jump into the kanji it unlocks.
start sprint ことばRead a real word
Finish a short session by reading one usable word chunk without spelling it out.
start sprint