Maki Kaji, the Japanese publisher credited with popularising the numbers game Sudoku, died of bile duct cancer in his Tokyo home on August 10. He was 69.
His death was made public on Tuesday by Nikoli, the puzzle publishing company Kaji co-founded in 1980.
“Known as the Godfather of Sudoku, he was adored by puzzle lovers around the world and we would like to express our gratitude to all of you,” Nikoli said.
Kaji was a university dropout who worked in a publishing company before starting Nikoli, Japan’s first puzzle magazine.
Sudoku's origins are open to debate. Some say the game can be traced back to the 8th century and arrived in the Arab world from China through India. Others credit Leonhard Euler, an 18th century Swiss mathematician, as the game's creator. Earlier versions of the puzzle were published in French newspapers in the 19th century. However, US architect Howard Garns is generally considered to be the creator of the game's modern version, establishing it in the 1970s under the name Number Place.
Kaji took inspiration from Number Place to create the beloved gridded numbers puzzle as we know it today. It was first introduced in Japan by Nikoli in 1984 as “Suji wa dokushin ni kagiru”, loosely translated as “the digits must be single”. The name was later abbreviated to Sudoku by Kaji.
"It was a very interesting puzzle, fun to solve," Kaji said in a speech during the 2008 US Sudoku Championship. "But the name, Number Place, did not hit me. I wanted to create a Japanese name."
Sudoku gained prevalence outside of Japan in the early 2000s when puzzle magazines in the UK began publishing the game, which made its popularity skyrocket. The World Sudoku Championships have been held annually since 2006.
Commended as a way of sharpening mental faculties, millions of people around the world have made a habit of playing Sudoku on a near-daily basis.
Kaji remained an active part of the company he co-founded, creating and improving puzzles until he stepped down in July owing to ill health. He was credited with inventing other puzzle games such as Masyu, a logic puzzle consisting of black and white circles in a grid.
“I get really moved when I see a new idea for a puzzle which has lots of potential,” Kaji told the BBC in 2007.
“It is like finding treasure. It’s not about whether it will make money, it is purely the excitement of trying to solve it.”
