Japanese puzzle maker Maki Kaji, pictured here in 2012, died this month from bile duct cancer. He was known as the "godfather of Sudoku" for his hand in bringing the puzzle to the masses.
CNN  — 

Maki Kaji knew better than most that the simple joys are sometimes the most fulfilling, even if they come in the form of numbers and squares.

Kaji was a man who loved watching and betting on horse races, spending time with his wife and publishing a magazine that featured puzzles for curious readers. A good puzzle, he believed, could be solved and enjoyed by enthusiasts of all ages and skill levels. They weren’t meant to make you think as much as they were meant to take you away from your world for a while.

The philosophy with which he lived his life – and made his puzzles – inspired him to rework an American puzzle into what would become Sudoku, one of the best-known and most widely played puzzles in the world.

“Sudoku is very, very special,” he told the BBC in 2007. “The problem is something like Sudoku only comes along once every 100 years.”

And Kaji, who called himself the “Godfather of Sudoku,” was a once-in-a-lifetime creator.

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. He was 69.

He handcrafted Sudoku puzzles

Kaji wasn’t always interested in puzzles, but he dreamed of helming a successful magazine. So he created the puzzle company Nikoli, which he named after a winning race horse, according to a 2007 New York Times article. 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.

He developed a number of puzzles with Nikoli, but his dalliance with Sudoku began in 1984. That year, Kaji came across a puzzle in an American magazine called “Number Place.” Kaji enjoyed solving the puzzle, but he had some notes.

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.”

“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.”

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. All it took was filing them in, completing the puzzle and erasing them again so the puzzle could be passed onto a new player.

“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. “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. I think you can find real joy from these things.”

Sudoku went global, but Kaji resisted international fame

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. By the mid-2000s, magazines in the UK, US and other pockets of the Western world were publishing their own Sudoku puzzles. But Kaji had only trademarked Sudoku in Japan – the rest of the Sudoku puzzles were copycats he didn’t have a hand in.

But that was all right with Kaji. ​​In his 2008 speech, he said he thought, “‘I would be happier to see everyone in the world enjoy Sudoku more easily.’” His hand-drawn style would have slowed down production time, after all, and Sudoku’s ravenous international players could hardly wait for a new puzzle.

Nikoli continued to publish magazines seasonally, which were often primarily made up of reader-submitted puzzles. Kaji resisted attributing meaning to the puzzles he published – they weren’t meant to instruct or even challenge those who attempted to complete them, he said in a 2006 interview with the Japan Times.

“They’re just for fun, for no reason, with no goal in mind,” he said.

The worldwide Sudoku boom delighted Kaji, but by that point, he’d already found contentment.

“I did not become a millionaire, but I’m glad Sudoku is now loved by billions of people,” he said at the 2008 championship. “I enjoy my staff saying they are proud of their job, I enjoy a glass of wine with my wife every night, and I enjoy horse racing every weekend. I am very much satisfied with the way I am.”

Kaji retired as Nikoli’s CEO in July, but the company promised to “continue to provide fun and engaging puzzles to the world.” Thanks to Kaji, fun and engagement are baked into the company’s DNA. He believed the care he put into each puzzle was evident to its player and more rewarding for its creator, and that there was beauty in a symmetrical puzzle.