Japanese is hell.

Koohī makes it bearable.

Reading is rough.

With a lack of shared vocabulary, etymology, and grammar patterns, reading the books you want to read in Japanese can be a difficult task.


Avg unique kanji in a children's novel


Avg unique words in a children's novel

Koohī fixes that.

Koohī is an SRS (spaced repetition system) learning resource designed around the idea of pre-learning content.

Learning vocabulary before it appears in a book eliminates the pressure to constantly have a dictionary open, leaving readers with a smooth reading experience.

A full-package, web solution

Machine-Assisted Learning

Koohī's Spaced Repetition System (SRS) ensures that you're studying the flash cards you need by adjusting review timers based on accuracy.

Prebuilt Decks

200+ prebuild decks, covering 30,0000+ unique words. All ready with the click of a button.


Add words directly from a dictionary, or even create your own custom cards.

Flexible Decks

Mix n' Match

All decks can be combined with others to create lists more conducive to the media you consume.

All Native

All decks built directly from native, Japanese media with words learnable in the order they appear in the source.

Flexible Filtering

Control the size of decks by filtering out according to factors such as word frequency.

Decks That Learn

All decks are dynamically synced to your account - learning words on one deck affects the rest, meaning everything is personalized to your needs.

A Modern SRS

No Multiple Choice

Koohī checks that you know your words by letting you type your answer, instead of by guessing easy multiple choice questions.

Pitch Accents

Assists in mastering pronunciation through the integration of pitch acccents, a linguistic feature normally reserved for specialized dictionaries.

Example Sentences

Example sentences gathered from novels appear during review sessions to help you nail down what definitions you can expect to see.


Have fun while learning through the introduction of semi-competitive aspects such as xp.

Graduate from textbooks with Koohī, free forever.