It took many years for Sudoku to become a hit in the rest of the world, but in the late-1990s, the puzzle started appearing in Western newspapers. Sudoku went global, but Kaji resisted international fame I think you can find real joy from these things.” “However, back in the day there were many things you can enjoy with no cost such as playing with stones or chalks and going to mountains. “Many people take it for granted that you would pay to enjoy yourself in this modern society,” he said in a 2012 interview with J-Collabo, an organization that helps Japanese people connect in New York. All it took was filing them in, completing the puzzle and erasing them again so the puzzle could be passed onto a new player. Sudoku’s appeal was its simplicity: Only the numbers 1 through 9 were used, none of the numbers could be repeated in a row of the nine-by-nine square and no math was required.

“I WAS already married at that time,” he joked in a speech at a 2008 US Sudoku championship.” And please understand that I did NOT come up with ‘Numbers should be single’ because I wanted to be single again.” So, before unveiling his own version of the puzzle to appear in an upcoming Nikoli magazine, he revised its design and renamed the puzzle Sudoku, which is a shortened version of a Japanese phrase that in English means “the number must remain single.” That year, Kaji came across a puzzle in an American magazine called “Number Place.” Kaji enjoyed solving the puzzle, but he had some notes. He developed a number of puzzles with Nikoli, but his dalliance with Sudoku began in 1984. Kaji enjoyed the fast-paced nature of horse betting, but he took care with his puzzles - they were all made individually by his Nikoli staff, rather than computerized and created via algorithms, a method he hoped would inject some individuality into the puzzles. So he created the puzzle company Nikoli, which he named after a winning race horse, according to a 2007 New York Times article. Kaji wasn’t always interested in puzzles, but he dreamed of helming a successful magazine. The publisher and puzzleman, whose Sudoku quietly entertained players in his native Japan and across the world, died this month from bile duct cancer, according to Nikoli, the puzzle magazine company he founded. And Kaji, who called himself the “Godfather of Sudoku,” was a once-in-a-lifetime creator.

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