Japanese Crossword Puzzles

A Japanese crossword is written in katakana, one kana per square, whatever script the word is normally written in. 経験 (experience) goes into the grid as its reading ケイケン, four squares; 猫 is ネコ, two. The long-vowel mark counts as a square of its own, so ギター (guitar) takes three.

Clues are called カギ, "keys": ヨコのカギ for across and タテのカギ for down. Answers can be as short as two kana, which English grids never allow, and in these puzzles 116 of the 421 answers are exactly that: ハシ, イス, ユキ.

Because the grid holds sounds, not spellings, one answer can stand for several words. ハシ is a bridge (橋), chopsticks (箸) and an edge (端); the clue decides which, and the crossing kana confirm it.

Japanese puzzles follow rules popularised by the puzzle publisher Nikoli⁠: two black squares may never sit side by side, across or down, and the black squares may never cut the white ones into separate pieces. Every grid here obeys both, with black squares on 22% of the board.

Those rules only work because kana cross easily. The answers on this site use 82 different katakana, and two random answers share at least one of them 32% of the time. That is far below English letters (79%), but more than ten times the Korean figure, where a crossing has to match a whole syllable block (2.6%). So a Japanese grid can interlock densely, and a Korean one cannot.

One convention works differently here. Japanese magazines write small kana full-size in the grid, so キョウ is filled as キヨウ. These grids show the small ョ, ッ and ャ as they are written, but the checker accepts the full-size kana too, so either way of typing is marked correct.

Every answer is a reading the JMdict dictionary marks as common, and a noun, verb, adjective or adverb in its dictionary form: ケイヤク (contract), イソガシイ (busy), ノリカエ (changing trains). Archaic, rare, slang and vulgar senses are left out, and so are particles and set phrases.

That filter matters because the word list behind the grids was ranked from film subtitles, which float up fragments like アイツ and conversational forms no crossword would use. 13,139 readings survive it, most of them three or four kana long.

The clues were written for these puzzles in ordinary mixed kanji and kana, the way a magazine カギ reads, and aimed at a casual solver rather than a quiz champion.