Japanese has a great many expressions made up of four kanji.  These are called 四字熟語 (よじじゅくご – yojijukugo).  That neatly self-referential term can be defined roughly as “four-character mature expression”.  Usually their meanings can be deduced from the kanji, but they are better considered idioms than words.  Many are sourced from Chinese and keep their original meaning, while others are native in origin.

Idioms add spice and colour to any language, and I think the addition of the kanji’s layers of meaning make this especially true of the 四字熟語.

Moreover, I believe that learning these can have the double purpose of learning kanji readings easily.  With every expression you get four readings, and they have a sort of built-in context, which makes learning them easy in the same way that learning phrases can be easier than learning individual words.

I have now taken the 401 most common 四字熟語 and made a shared deck for you anki users.  Search for “yojijukugo – 401 most common”.  There are three other 四字熟語 decks as well, but obviously mine is the best 😉  Big thanks to Kanji Haitani for providing the source material, and to BlackDragonHunt for parsing it into a tab-delimited file and saving me hours of work.

Eventually I want to upgrade this deck with example sentences, but this will do for now.

Edit: here are the kanji statistics for this deck.

The 401 cards in this deck contain:

• 718 total unique kanji.
• Old Jouyou: 643 of 1945 (33.1%).
• New Jouyou: 15 of 191 (7.9%).
• Jinmeiyou (reg): 21 of 645 (3.3%).
• Jinmeiyou (var): 0 of 145 (0.0%).
• 39 non-jouyou kanji.

Jouyou levels:

• Grade 1: 66  of 80  (82.5%).
• Grade 2: 100 of 160 (62.5%).
• Grade 3: 92  of 200 (46.0%).
• Grade 4: 90  of 200 (45.0%).
• Grade 5: 68  of 185 (36.8%).
• Grade 6: 57  of 181 (31.5%).
• JuniorHS: 170 of 939 (18.1%).

JLPT Levels:

• JLPT 4: 82 of 103 (79.6%).
• JLPT 3: 107 of 181 (59.1%).
• JLPT 2: 276 of 739 (37.3%).
• JLPT 1: 178 of 922 (19.3%).
• 75 non-JLPT kanji.

==================

Update 2011-12-10:

A quick follow up on this is probably in order, since people still view this post from time to time it seems. It must be said that the original deck was, for me, an abject failure. Learning more than one reading in a card is a very very bad idea. However; now, much later, when I’ve gotten a great many readings under my belt already, I’ve come back to the 四字熟語 – not this deck, but the deck at readthekanji.com – and now, it’s really coming together. Usually when a new card comes up, I’ll know all the readings maybe a third of the time, three of them another third or so, occasionally two, and almost never one or none. So now my brain can find a home for that new reading, the 四字熟語 with its full reading and meaning, and usually only one reading is unknown or weak. Now that built-in context can really set to work.

So if you’ve come to this page looking for a shortcut for kanji readings, apologies but this isn’t it. There really isn’t one; but, once you’re at more of an intermediate level, with perhaps a solid knowledge of readings for a thousand characters, not all of them per character but the common ones, and some exposure with a bit of recollection for a few hundred more perhaps, at that point studying these 四字熟語 for both their own value as idiomatic expressions and for kanji readings will prove to be of great benefit.