The puzzle enthusiast and publisher is credited with turning the grid-based maths problem into a worldwide phenomenon

Maki Kaji, a Japanese publisher who popularised the numbers puzzle sudoku played daily by millions around the world, has died from cancer aged 69.

A university dropout who worked in a printing company before founding Japan’s first puzzle magazine, Kaji took hints from an existing number puzzle to create what he later named “sudoku” – a contraction of the Japanese for “every number must be single” – sometime in the mid-80s.

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