Sudoku creator Maki Kaji, whose life’s work was spreading the joy of puzzles, has died at age 69 of cancer.

Known as the “Godfather of Sudoku,” Kaji created the numbers puzzle to be easy for children and others who didn’t want to think too hard.

He founded his puzzle company, Nikoli Co., in 1983 and created the game around the same time.

Sudoku became a global hit two decades later after a fan pitched it to the British newspaper The Times.

His company said Kaji traveled to more than 30 countries spreading his enjoyment of puzzles.

Sudoku championships have drawn millions of players and his company has provided more original puzzles to media companies in Japan and abroad.