The most efficient way to remember the meaning and writing of Japanese characters.


Remembering the Kanji

Use your imaginative memory to remember thousands complex Japanese characters, with Remembering the Kanji by James W. Heisig.

Get it at

Try the sample chapter (includes 294 kanji).
Both the 5th and 6th editions are supported!

Review, Share and Improve!

See your progress Visualize your progress as stacks of flashcards. Reviews are automatically scheduled based on your past results.

Review the kanji Review the kanji online. Repeat more of the difficult characters, and less of those that you know well.

Share mnemonics Feeling stuck? Share stories with fellow learners. Find help and encouragement on the community forums!


The new forum is LIVE!15 November 2015
Finally. It was a lot of work but I am really happy today to introduce the upgraded and redesigned kanji koohii FORUM !

The forum is now mobile device friendly (phones and tablets)! Early Google PageSpeed Insight results are promising. No more pinch and zoom. You can now browse all discussions, and participate on a mobile device with resolutions all the way down to 480 pixels wide.

I wanted the mood of the forum to change, from the somewhat dry and rhetoric look (in my eyes, anyway), to something a little more colorful with hints of cherry inspired of course by Japan :) I didn't want to go full "flat design" though, so there are shadows and layers, and I will continue to refine it over time. I am not a graphic designer, so the design is a bit weak and inconsistent in some areas but overall I think it's a decent upgrade :)

Along with the responsive layout and refreshed design, the forum now supports a Rich Text Editor, private messaging, video embedding in posts, a printable version of threads, etc.
Forum Upgrade!7 October 2015
The forum is finally being upgraded to a better platform (MyBB) that allows PMs (private messaging), reputation, likes and thanks, a rich text editor, video embedding inside posts, etc.

Update : I wasn't happy with the new forum theme and completely re-designed it. Spent a week creating new designs in Photoshop and I'm currently "slicing" it into a functional theme which takes a lot of time. It's honestly taking far longer than I wish but hopefully it will be worth it. The new forum and theme will work better on mobile devices, which could also help with traffic since Google now ranks "mobile" friendly websites differently when searching on mobile devices.

Thing is, I could have used an existing theme, perhaps even bought one. But forums are also slowly being outfashioned by Q & A sites, the Reddit / HackerNews format etc. So I wanted to try a variation on the forum idea. Since most people just go straight to "Recent posts" or "Show new posts" I modified the index page to show all recent topics instead. That means all the new discussions are always on the front page. The forums are available as "categories" in the sidebar. It's a lot of work but I think it was long overdue and hopefully it will help the forum thrive in the medium to long term!
Database maintenance23 September 2015
The website was unavailable for ~15 mins today. I realized it's been a while since run the optimize functions on the database. It seems to have helped... though not by much.

The cache of the shared stories list is a good improvement, however it only saves one relatively expensive query. There is another similar query for the "Recent Stories" that is not cached yet, and I suspect this one also causes a lot of slow down.

I'm going to investigate the design of the database. I've never studied MySQL thoroughly since my main interest in web development is the front end side (Javascript, Css, etc). However I need to catch up on optimization techniques because the stories table is nearly one gigabyte and it keeps growing. Something is not quite right with the way I've designed the table, or the indexes.

Just how effective is the Shared Stories cache?21 September 2015
Today I implemented a simple log for the cache and a corresponding report in the "administration" panel for the website. As you can see the Study page caching, which was meant to improve the page loading time, hasn't been very effective so far:

That's because the cache only lasted an hour, and with visits spread across thousands of kanji pages, the cache typically wouldn't last long enough for another visitor to benefit from it.

I've now set the cache of the shared stories list to 12 hours, and the effectiveness is closer to 30% as of writing. Now I have real numbers, and hopefully we will see at least every second request to the Study page to benefit from the cache.

Small fixes following yesterday's update18 September 2015
The timezone setting for the server was set incorrectly, so that due cards and "reviewed today" count would not update at the usual time. This is now fixed. Remember to restore your timezone setting in the Account page if you tweaked it yesterday. Thanks for faneca and Daniel for the report!

Update : three minor fixes:

  • Fixed broken /sightreading URL
  • Fixed broken article link in Manage page to the RTK Supplement news update
  • Fixed error when clearing the learned kanji list ("Clear" in Study sidebar)
I haven't got any other emails since the update so it looks like the update went smoothly!

...more in the news archive.