Kaeru teaches Japanese writing, grammar, and pronunciation in one app. No juggling five tools. No guessing which resource covers what. You open Kaeru and study.
WRITE KANJI FROM MEMORY
Most apps show you a character and ask you to pick the right answer. You pass the quiz and feel confident. Then you face a blank page and draw nothing.
Kaeru puts you in front of that blank page from day one. You draw each character stroke by stroke, building recall that transfers to real writing. 13,108 kanji with correct stroke order. Every character includes native audio, readings, and meanings.
iPad users: Apple Pencil turns your screen into a kanji notebook.
GRAMMAR THAT EXPLAINS ITSELF
828 grammar patterns from N5 to N1. Formation rules, context, example sentences, and audio for every pattern. Browse by JLPT level or search for a specific construction.
You read は vs が in 50 different patterns instead of one confusing chart. Particles click when you see them used, not described.
SRS THAT ADAPTS TO YOU
Skip two days with most SRS apps and you return to 200 pending reviews. The pile grows. Motivation drops. You quit.
Kaeru's spaced repetition tracks your memory for each item and schedules reviews before you forget. Strong items space out. Weak items repeat sooner. Miss a few days and the system adjusts instead of punishing you.
DAILY JAPANESE STORIES
A new story every day, matched to your JLPT level. Native audio at adjustable speed. Tap any word to translate. Grammar breakdowns for every sentence. A comprehension quiz at the end.
Stories put your kanji and grammar into real context. You see characters used, hear them spoken, and test yourself.
PRONUNCIATION SCORING
You study for months, open your mouth, and the words come out flat. Nobody corrects you.
Kaeru's AI coach listens. Record yourself and get scored on pitch accent, fluency, and accuracy. Feedback after every attempt. Fix pronunciation problems before they become habits.
JLPT N5 THROUGH N1
Curated decks for every JLPT level covering kanji and vocabulary. Each deck maps to your target exam. Track your progress toward a specific level so study hours count on test day.
BUILT-IN DICTIONARY
Search by romaji, hiragana, kanji, or English, Spanish, Korean. Every entry shows readings, meanings, JLPT level, and stroke count.
ONE APP INSTEAD OF FIVE
Grammar reference. Kanji handwriting. Vocabulary decks. Spaced repetition. Pronunciation scoring. Daily stories. Dictionary. Progress tracking. One subscription covers everything.
Stop splitting your study across a kanji app, a grammar app, a flashcard app, and a pronunciation tool you opened twice.
Who uses Kaeru: learners who want to learn hiragana and katakana. JLPT test preppers from N5 to N1. Anyone tired of recognizing kanji without being able to write them.
All features require a subscription or one-time purchase.
Privacy Policy: https://kaeru-jp.app/privacy-policy
Terms of Use: https://kaeru-jp.app/terms-of-use
There should be an option to select unknown words in the story and at the very least see the furigana. I can’t record the story if I don’t know the reading. Also when searching in the dictionary, there’s no way to close the keyboard. It stays open and the only way to exit the dictionary is a force quit. This has the potential to be a great resource, but these two issues are a huge problem for me.
デベロッパの回答
Hi PC812 - update on your first point: the latest version puts furigana above the kanji in reading practice, so you can read a story and record it without getting stuck on a reading. Full tap-to-lookup on individual words isn't there yet, but it's still high on the list. And the dictionary keyboard that wouldn't close - if that's still happening after you update, let us know at support@kaeru-jp.app so we can make sure it's sorted on your end. Thanks again for flagging these, really helpful.
No trial without locking in payment
高円寺北
We need to stop this sleazy practice of making people commit to a payment to try an app. It is the developers’ responsibility to impress us with the quality of the app without asking for us to gamble in return.Response: I don’t misunderstand the system - I just reject it. You are putting the user in a position to have to remember to cancel a payment when you haven’t yet demonstrated your product. It’s lazy and unacceptable. Do better.
デベロッパの回答
Hi, thanks for the feedback - but we want to clear up a misunderstanding. Kaeru’s free trial doesn’t lock in any payment. You can start it, use the full app, and cancel anytime in your Apple ID Settings before it ends - Apple won’t charge you, and there’s no commitment. This is the standard Apple trial model, not a sleazy practice.We chose a subscription with a free trial because it lets us keep the app ad-free, sell no user data, and keep shipping new content. We understand it’s not for everyone, and that’s a fair preference - but “gambling” isn’t an accurate description of how it works.
Great idea but buggy execution
¥vonne_
The screen crashes when I try to write the kanji. I am asked to practice stroke but I don’t know how to say that 14 stroke kanji, so have that functionality. I will try this app for the next three months and support you in your journey of building it
デベロッパの回答
Hi ¥vonne_ - good news on both fronts. The writing-practice crash is fixed: it came from the initial setup getting interrupted before the kanji data finished unpacking, and the app now catches that on launch and finishes the unpack itself - no more delete-and-reinstall. The kanji's on-yomi/kun-yomi readings also show right in the deck now, where they used to be hidden, so you always know what you're writing. Update to the latest version and you should be set. Thanks again for sticking with us through it!
Scam
KantanSan
App has no real free trial period and forces you to cash in right away after setting up profile. Tiring, unprofessional and just a money grab.
デベロッパの回答
Thanks for the feedback. We understand that this setup can feel frustrating 🙏We offer a free trial so users can try the app before paying. On the App Store, Apple may still require a payment method to activate the trial — this is handled by Apple, and we never receive your payment details.
Kaeru 2.1 keeps your progress with you, on every device.
• Sign in with Apple to keep your words, kanji, streak and progress safe and in sync on your iPhone and iPad.
• Made for iPad: a sidebar, your Dictionary results and the word side by side, and more room for lessons, flashcards and your decks.
• Use Kaeru sideways on iPad and iPhone.
• Keyboard shortcuts on iPad, like Space to flip a flashcard and ⌘F to search.
• Pronunciation scores arrive faster.
Plus bug fixes and small improvements.
