Finding the answer from diverse angles
Becoming absorbed in the joy of number puzzles

I became interested in numbers as soon as I understood what they meant, but my real passion for numbers began when I came across a number puzzle as a junior high school student. I was particularly interested in arithmetical restorations, and when I was a high school student, I started taking on arithmetical restorations in which all the digits were erased. When I joined the Faculty of Science at Kyoto University, I became obsessed with the idea of creating an even bigger arithmetical restoration myself. I thus devoted myself to research on these puzzles and successfully created a completely blank arithmetical restoration puzzle in which the answer was to more than 20,000 decimal places. I set out to publish the puzzle, which was around 200 m long, in a magazine for which I would later become chief editor—Puzzle Communication Nikoli.

Puzzle Communication Nikoli encouraged its readers to send in their own puzzles, and as a puzzle creator myself, I sent in many of my own. My huge puzzle was well-received, and with a newfound confidence, I approached the then-president of Nikoli Maki Kaji to ask whether I might be able to join the company. Perhaps thinking that Nikoli wasn’t the best place for a Kyoto University-educated student, Kaji was initially opposed to the idea, but I pleaded with him and was ultimately hired.

Following on from the success of sudoku
A duty to popularize number puzzles worldwide

In 1999, my ninth year at the company, I became chief editor of the puzzle magazine Puzzle Communication Nikoli. Although my time as chief editor was fulfilling, there was no real change. Huge change, however, came in 2005 with the worldwide sudoku boom, kickstarted with the inclusion of a sudoku puzzle in the British newspaper The Times. As a result, Nikoli’s popularity among global media outlets grew. That said, while there was indeed a sudoku boom, it was only really among fans of puzzles. I felt Sudoku hadn’t yet got to the stage where it was a familiar puzzle that could be enjoyed by all.

For me, this changed when sudoku found popularity among senior citizens in Otsuchi Town in Iwate Prefecture (an area which had suffered significant damage from the Great East Japan Earthquake) as a form of brain training . In 2017, Otsuchi Town went on to host a hugely successful Sudoku Certification Exam, which was taken by a broad range of individuals from age 6 to age 99. This helped me realize that puzzles can be a key element of education for both children and senior citizens. Today, having taken over as president from Kaji, I believe it is my duty to develop number puzzles into an activity that truly can be enjoyed by men and women of all ages and nationalities.

One of the appeals of Kyoto University is that it provides an open environment for eccentric individuals to do what they like, and with freedom. I hope this doesn’t change, and I look forward to the university continuing to develop and produce individuals who go onto accomplish interesting things.