Maki Kaji, who added to the world’s joy and frustration by inventing Sudoku, dies at 69

Sudoku creator Maki Kaji
Maki Kaji, known as the Godfather of Sudoku, has died at 69.

Maki Kaji, who created Sudoku during a lifetime’s commitment to spreading the joy of puzzles, has died, his Japanese company said Tuesday. He was 69 and had bile duct cancer.

Known as the “Godfather of Sudoku,” 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 The Times of London. Two years later, Japan rediscovered its own puzzle as a gyakuyunyu, or reimport.

Kaji was chief executive of his puzzle company, Nikoli, until July and died Aug. 10 at his home in Mitaka, a city in the Tokyo metro area. The New York Times reported he was born in 1951.

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


Sudoku was never trademarked except in Japan, driving the overseas craze over it, Nikoli said.

Maki Kaji took an American game and turned it into Sudoku. But he

May 24, 2009

“Kaji-san came up with the name Sudoku and was loved by puzzle fans from all over the world. We are grateful from the bottom of our hearts for the patronage you have shown throughout his life,” the company said in a statement.

Originally, Sudoku was called Suji-wa-Dokushin-ni-Kagiru, which translates as “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.

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.

Yoshinao Anpuku, who succeeded Kaji as Nikoli’s chief executive, said Kaji made friends easily and had a “unique and playful approach toward life.”


“Our mission is to pursue Maki’s vision and possibilities,” Anpuku said.

Nikoli has provided original puzzles to more than 100 media companies, 10 of them foreign ones.

Japanese newspaper Mainichi, in its obituary of Kaji, credited him with spawning the puzzle sections in bookstores, as well as introducing the word “Sudoku” into the Oxford English Dictionary.

Kaji is survived by his wife, Naomi, and two daughters.