Kotsu コツ
Japanese that actually clicks.
Kana, radicals, kanji with etymology, vocabulary — one connected study system built for the long game.
Etymology Spotlight 1/5
日 (sun)月 (moon)
Sun and moon together — two sources of light combining to make brightness. One of the clearest pictographic recipes in the language.
Explore kanji → What's in Kotsu
Five interconnected modules, each building on the last.
Radical Recipes Parts become meaning.
Every kanji is assembled from smaller pieces. Once you see the logic, you can read thousands of characters by feeling rather than memorizing.
three trees become forest
person leaning against a tree
stone at the foot of a mountain
The Study Loop How Kotsu works.
01 Shape See the character and its visual form
02 Sound Connect the sound or reading
03 Combine Spot it inside compounds and recipes
04 Read Recognize it in a real word
Start here 0/46 items Beginner
Course Map
The full path.
0% complete 0/283 items
Beginner
Radicals
Kanji
Words
Course Tree
A trunk for required order, branches for nearby ideas. Follow the numbers.
1 Sound Seeds あいうえお Beginner Build the first sound map with simple, repeatable kana shapes. あいうえおかきく Ready 2 Sound Branches 濁音 Beginner Add marks and small kana so one shape can open into nearby sounds. がぎぐげござじず Ready 3 Borrowed Sound Map カタカナ Beginner Map familiar sounds onto sharper katakana forms. アイウエオカキク Ready 4 Borrowed Sound Branches ダクオン Beginner Finish the sound system with marked katakana and compact blends. ガギグゲゴザジズ Ready 5 Nature Radicals 自然 Radicals Learn the picture-words children meet early: water, fire, tree, sun, moon, mountain, river, rain. 水火木金土日月山 Ready 6 People And Body からだ Radicals Study the radicals that show bodies, hands, mouths, eyes, hearts, strength, and family. 人口目手心力女子 Ready 7 Things That Act 道具 Radicals Add radicals for field, thread, speech, food, vehicle, and gate. 田糸言食車門 Ready 8 Counting Kanji 一二三 Kanji Move from simple strokes into the first number kanji. 一二三四五六七八 Ready 9 Nature Becomes Kanji 日月火 Kanji Turn familiar radicals into full kanji with readings attached. 日月火水木金土 Ready 10 Body, Size, Place 人大小 Kanji Learn kanji that describe people, scale, direction, and time. 人大小中上下年 Ready 11 First Words はじめて Words Read the kinds of words a child hears early, using kana you already know. ママパパはいワンワンニャーニャーおいしいいたいすき Ready 12 Social Words あいさつ Words Finish the first course loop with greetings and polite everyday phrases. こんにちはありがとうごめんなさいさようならおはよう Ready