Where the name Sudoku comes from

Updated 2026-10-05

A long name, cut short

When Nikoli introduced the puzzle in Japan in 1984, it called it Sūji wa dokushin ni kagiru, roughly "the digits must be single", or more playfully "the numbers must stay unmarried". The name was later shortened to Sudoku: su means number and doku means single. Nikoli's president Maki Kaji came up with the name; his colleagues talked him into the short form.

Sources: Nikoli: Sudoku, Wikipedia: Maki Kaji

Number Place and Nanpure

Before it had a Japanese name, the puzzle already had an English one: Dell Magazines published it in 1979 as Number Place. In Japan, Sudoku is a registered trademark of Nikoli, which is why other Japanese publishers use Number Place, written ナンバープレース, or the short form Nanpure (ナンプレ).

Sources: Wikipedia: Sudoku, Nikoli: Sudoku

Su Doku in London

When The Times in London launched the puzzle on 12 November 2004, it printed the name as two words, Su Doku. Nikoli writes it as one word, Sudoku.

Sources: Wikipedia: Sudoku, Nikoli: Sudoku

Sources

All articles →