’Father of Sudoku’ Maki Kaji, who saw life’s joy in puzzles, dies

The man dubbed the "father of Sudoku" for his role in popularising the numerical brainteaser loved by millions, has died of cancer at 69, his Japanese publisher has announced. He was 69 and had bile duct cancer.

Kaji created the puzzle to be easy for children and others who didn’t want to think too hard. Its name is made up of the Japanese characters for “number” and “single,” and players place the numbers 1 through 9 in rows, columns and blocks without repeating them.

Ironically, it wasn’t until 2004 when Sudoku became a global hit, after a fan from New Zealand pitched it and got it published in the British newspaper The Times. Two years later, Japan rediscovered its own puzzle as a “gyakuyunyu,” or “reimport.”

Kaji was chief executive at his puzzle company, Nikoli Co., until July and died Aug. 10 at his home in Mitaka, a city in the Tokyo metro area.

Maki traveled to more than 30 countries spreading his enjoyment of puzzles. Sudoku championships have drawn some 200 million people in 100 countries over the years, according to Tokyo-based Nikoli.

Sudoku was also never trademarked except within Japan, driving its overseas craze, Nikoli said.

Originally, Sudoku was called “Suji-wa-Dokushin-ni-Kagiru,” which translates to, “Numbers should be single, a bachelor.” In recent years, Sudoku, believed to be the world’s most popular pencil puzzle, has come out in digital versions.

Sudoku requires a player to put the numbers one to nine in a box made up of 81 squares so that no number is repeated in any of the nine vertical or horizontal lines.

To complicate matters further, the grid is also sub-divided into nine blocks containing nine single squares, and each block must also contain the numbers one to nine.

Born in the main northern island of Hokkaido, Maki started Japan’s first puzzle magazine after dropping out of Keio University in Tokyo. He founded Nikoli in 1983, and came up with Sudoku about the same time.