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 know 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
I was happy to try the app for a bit and it was working fine but now whenever I open it, it hangs on the kanji loading page. I deleted the app and reinstalled, same issues. Consistent across my iPhone and iPad. It’s a shame.
Developer Response
Thanks for the thoughtful feedback - sorry the kanji loading page is hanging on both your iPhone and iPad. That's not expected, especially after a reinstall. Could you email support@kaeru-jp.app so we can dig into it? Your iOS version and any error details would really help us track down the cause. 🙏
I wanted to love this app
Matzaball
Has some potential, but the daily exercises have some inaccuracies that shouldn’t be there and the vocab training with kanji acts very strangely. Some cards have just a kanji and no associated task or prompt. The English translations are off and the voice readings are also frequently different than what’s written. And some sentences don’t make sense in Japanese or English. I also get annoyed by constantly being rated at 80% in pronunciation when my individual scores during the test are above 90%. I’m glad I only got a month subscription. Going back to Bunpo and Wanikani.
UI leaves a lot to be desired
killuawatts
The app has a clean interface making you think it’s easy to use but far from it. If you want to just use it as a review before you dive into your exact it’s tedious since it makes you record the word without the ability to just automatically swipe and if you skip it makes it seem like you don’t know the word. There’s no easy access to review JLPT material but rather everything is scattered across decks in one location. Organization feels sloppy despite the clean looking interface. Feels like a trick
Developer Response
Thanks for the thoughtful feedback. Sorry the review flow and deck organization feel clunky — the "skip vs. don't know" distinction and scattered JLPT material are fair points we're weighing. If you email support@kaeru-jp.app with how you'd like to review, it really helps us prioritize. 🙏
Kanji writing needs improvement
Freezeyxdwdt
I think that this app has potential. However it is annoying that the screen shakes whenever a stroke is considered wrong on a kanji. It really is distracting and hard on the eyes, especially when the stroke is mostly right but is just judged as incorrect by the algorithm. Letting the stroke fade into the background and ticking up a small counter for error strokes could be better. Shaking the screen is disruptive.
Developer Response
Hi Freezeyxdwdt, thanks for the thoughtful feedback - and good news: 1.4.6 just shipped with the screen shake significantly toned down for incorrect strokes. Should be much less disruptive now. Your suggestion about fading strokes and a small error counter is interesting too - we’ll keep iterating on the feedback design. Give the update a try and let us know if it feels better!
Fixed
• On iPhones with iOS 26, the N5 course could freeze for several seconds when you opened it and during some lessons. The more units you had finished, the longer it froze. It now opens and runs without the wait.
• For some people, the app closed when they opened the Library. This is fixed.
• Some example sentences on flashcards and in the dictionary showed the wrong reading above a word, and Listen read it that way too. About 300 examples now show and read the right one.
• With the Kaito voice, a few words and one kanji reading played the wrong recording. The app now downloads a small fix for them.
• A word with more than one reading could play the recording of another reading (for example 人 as ひと instead of にん). It now plays the reading you see.
• In Daily Journey speaking practice, Listen could read some kanji in the sentence wrong. It now reads them the way the story does.
Version 1.6.1
The developer, Rozemyne Ltd, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
Contact Info
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
User Content
Identifiers
Usage Data
Diagnostics
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
