Inside Kaji Maki's Philosophy — placing puzzles as entertainment, never education

Intro — the man who "just found it and gave it a name"

Kaji Maki (1951–2021) was the editor and businessman who launched Japan's first puzzle magazine, Nikoli, in 1980 and incorporated the company of the same name in 1983. In 1984 he ran a puzzle he had found in an American magazine — "Number Place" — in his own pages, and christened it sudoku, a contraction of suji wa dokushin ni kagiru, "the numbers must be single." The name now travels in more than a hundred countries. He did not, however, invent the puzzle, and he corrected people on that point for the rest of his life.

I want to write about him now because he is that rare figure who stood not on the making side of puzzles but on the placing side. He was barely involved in puzzle construction himself. And yet Nikoli's puzzles carry a philosophy anyone can recognise. How do you put a philosophy into work you don't make? That is worth thinking about.

This is a study of the person, not a game write-up. He is no longer with us, so I want to handle him with more care than usual. I quote only from primary sources whose text I verified, and I keep his own words, third-party testimony, and my own reading strictly apart (The Independent / Japan Focus 2007 ↗ / iNTOUCH via Tokyo Reporter 2010 ↗ / Jonetsu-Shacho 2012, in Japanese ↗ / J-Collabo 2012 ↗ / Nikkei 'Bunka' column 2014, English translation ↗).

Background — tennis, horses, a print shop, and one magazine

Born in Sapporo and raised in Tokyo, Kaji spent his school years on tennis courts. He reached the last eight at his final national athletic meet, then cramped mid-match and lost on stamina. "I was made to understand that with my physique I could climb no higher. It was the first setback of my life," he recalled (Jonetsu-Shacho 2012 ↗). He dropped out of university and lived, by his own account, on day labour, mahjong and horse racing until around 23.

He then worked at a magazine publisher and a printing company. The strain perforated his stomach; he married the woman who nursed him. He told all of this cheerfully. The turning point came in 1979, when a childhood friend brought him an American puzzle magazine as a souvenir. A year later he checked properly and found nothing like it in Japan. "If it doesn't exist, then make it and it will sell — that's what I thought" (Jonetsu-Shacho 2012 ↗). He published the first issue in 1980, aged 29.

The point to hold onto is that he was not a puzzle obsessive who turned professional. In the J-Collabo interview too, the trigger is the absence of a puzzle magazine in Japan, not a love of puzzles as such (J-Collabo 2012 ↗). What he first saw was not a puzzle but an empty shelf. That origin explains almost every decision he made later.

Philosophy — not education, entertainment

Across every interview, the most consistent claim is this: a puzzle is entertainment, not education or training. In 2007, explaining how Nikoli decides whether to run a game, he said: "We're not trying to make something educational. It is better to think of what we do as entertainment" (The Independent / Japan Focus, 2007 ↗).

The stance has a source. In a 2014 piece he wrote himself for the "Bunka" column of the Nikkei, he describes a letter from a woman in her late forties. Caring for her ailing mother, she wrote that the fifteen minutes of sudoku before bed were her only distance from reality. "When I read this letter, I promised to myself that I would never use a scheme, like saying that it is for brain training or to prevent dementia, to sell sudoku. All I wanted was for people to just readily enjoy it" (Nikkei, 25 Aug 2014, English translation ↗). He took down the most profitable sign himself.

He put the same claim differently in 2010: "Training makes you stressful because you feel pressure to solve something, but sudoku is different. You can play just as long as it suits you. In that sense, it is like watching a movie" (iNTOUCH 2010 ↗). And in 2012, to the effect that he wanted people to find their own way of enjoying sudoku rather than use it to train the brain (J-Collabo 2012 ↗). Seven years, no drift.

One more statement is unusually clear as design theory: "We make the entry point for each game relatively easy but the exit point difficult, so that ordinary people can join in" (2007 ↗). His stated aim back at the founding was "not too hard, not too easy" (Jonetsu-Shacho 2012 ↗). Prioritising the entrance runs through his whole career.

Obsessions — the solving process, not the solved result

A short piece published under his name on Nikoli's site, "Choose wisely," carries his obsession in a single line: "All the time, we have thought more about the solving process than the end results. This is a question of good taste – an issue that computers will never comprehend" (Nikoli, "Why hand made" ↗). The same text ends: "You may invent a program to create Sudoku puzzles, but you will never create Nikoli's Sudoku puzzles." Provocative, but consistent.

The insistence on handmade puzzles was never about quality control; it was about authorship. "We make up the puzzles by hand, not on computers, because then the character and individuality of the writer are allowed to come out" (2007 ↗). In 2012 he said, in effect, that Nikoli had six hundred sudoku authors, that each puzzle has a different character depending on who made it, and that solving one feels like watching a fifteen- to twenty-minute short film (J-Collabo 2012 ↗). A puzzle, to him, was a signed work, not an anonymous problem.

Hence the recurring motif of dialogue between author and solver. In 2010 he described solving a handmade sudoku as a tacit dialogue between the two, adding: "To solve one requires logic. It is not a matter of trial and error" (iNTOUCH 2010 ↗). In the 2014 Nikkei piece he writes to the effect that creators try to surprise solvers, solvers enjoy the creators' particularities, and this mutual relationship is what makes puzzles evolve (Nikkei 2014, English translation ↗).

Then there is reader submission. Most puzzles printed in Nikoli came from readers — around 80% as of 2010, with roughly a thousand arriving each month for an editorial team of about twenty to sift and tune (iNTOUCH 2010 ↗). He also said, in substance, that even before the internet they were communicating with their customers, and had built a two-way relationship unlike foreign magazines that merely printed a puzzle and said "solve this" (ibid.). What he built was not a puzzle but a machine that puzzles arrive at.

Failures, and how he carried them

Start with the failures he spoke about publicly. The first issue: the three founders pooled their money, printed it at his employer's shop, and only when he held the finished magazine did he notice they had forgotten to print a price on it (Jonetsu-Shacho 2012 ↗). He also recalled that roughly one bookshop in ten agreed to stock it.

Then the failure of never knowing what will land. "We have no idea what makes something popular, so we try them out on the readers." "About once every five years, one suddenly takes off. It's as big a surprise to us as anybody else" (2007 ↗). A quarter of a century in, he freely admitted the formula had escaped him.

And the big one: no overseas trademark for sudoku. He had registered the name only in Japan. In the 2014 Nikkei piece he wrote: "The reason why sudoku got this popular is probably because it was not trademarked. The US newspaper New York Times expressed this as a brilliant mistake. It made me genuinely happy" (Nikkei 2014, English translation ↗). Back in 2007 he had already said: "More than the money, it is gratifying to see the explosive worldwide growth of our puzzles. That makes me very happy" (2007 ↗).

Here I want to flag something. That framing — "it was not trademarked" — sits slightly askew from later third-party testimony. Gotō Yoshibumi of the Japan Sūdoku Association says that in spring 2005 he and Kaji travelled to Britain intending to secure a trademark, and gave up when the name was judged to have become a common noun. Gotō adds that Kaji was "grinning and bearing it to a certain extent" but ultimately said it was best that as many people as possible were getting to enjoy sudoku (nippon.com 2021, Gotō's testimony ↗). He did not decline to register it; he went and failed. I don't think his own account is a lie. I read it as the trace of how long it took him to accept a loss and give it a meaning.

Dilemmas — the further it spread, the less he could reach it

The first dilemma is the asymmetry between reach and revenue. The more the world played sudoku, the smaller Nikoli's slice. In 2007 the company turned over about $4m with 22 staff; by 2010 its share of the global sudoku market was reported at roughly 5% (2007 ↗ / iNTOUCH 2010 ↗). Being the godfather and making money were, in his case, nearly unrelated.

Second: whether to grow. Offers to buy him out or scale him up arrived several times a year. "I want to keep the company small and compact, like a submarine with a small family of employees who are close." "I like the idea of a specialist home-made cake shop that runs out at 3 pm, and then we all just go home" (2007 ↗). Those are the words of the man who kept saying no. And yet the same article records him making a dozen trips a year to Europe and America, harangued by publishers for a follow-up hit. The man who wanted to stay small was circling the globe.

Third: handcraft versus demand. Twenty-odd people cannot supply the world. There is a recorded counter-argument here. Wayne Gould, who took sudoku to Britain, broadly agrees about handmade puzzles but says, in substance, that computer-generated ones spare you the setter's preferences — every puzzle is fresh, and no preconception or knowledge of past puzzles helps you (iNTOUCH 2010 ↗). Kaji's "authorship" is, flipped over, "predictability." I could not find a record of him answering that objection head-on.

Fourth: the distance he kept from education. Sudoku is used in maths classes worldwide and he was invited into schools. He noted that he used to be asked to lecture in maths classes but was increasingly called to science and art events outside them, and said in effect that although sudoku is often put to educational use, he wanted people to play it their own way rather than as brain training (J-Collabo 2012 ↗). He never refused the demand; he just refused to hang the sign. Not elegant, but coherent.

Influences — one American magazine, and the racetrack

The influences he acknowledged are surprisingly few. First, the puzzle magazine a friend brought him from America in 1979 — and then "Number Place," which he found in a US magazine in 1984. He wrote that he opened an American puzzle magazine he had been carrying on the train home after losing at the races. Not being good at English, he jotted down numbers without reading the instructions and solved it. Wasn't this fun? He bought a stack of back issues at Maruzen, tried making one himself as an experiment, and could (Nikkei 2014, English translation ↗).

He was always explicit that he was not the inventor. Gotō Yoshibumi testifies that Kaji was embarrassed whenever he was introduced as the creator at overseas events, and kept explaining: "No, I just found it and gave it a new name" (nippon.com 2021 ↗). The same article names the American architect Howard Garns as the creator of Number Place.

The second influence is horse racing. The company took its name from an Irish racehorse that won the 2,000 Guineas in 1980. He talked about betting and puzzling as plainly the same pleasure: watching a race finish is like trying to solve a puzzle — "The excitement of not knowing how it is going to end up is similar" (2007 ↗). In the same piece he says he limited himself to about ¥10,000 a day, calling it an exercise in self-control.

Third, his working years in publishing and printing. He said that having worked at both made it easier to produce a first magazine he had never made before (J-Collabo 2012 ↗). His foundation was not an apprenticeship in puzzle construction but a practical feel for paper and cost. That, too, is part of why he stood on the placing side rather than the making side.

Kizuki's reading — an editor who gave signatures to anonymous problems

From here on this is my reading, not his words. I read Kaji Maki less as a designer than as the editor who introduced the concept of an author into the puzzle form. He barely made puzzles himself. The three things he repeated — handmade, the solving process, the dialogue between author and solver — all reduce to a single operation: attaching a human signature to each individual problem. He took an anonymous time-killer from the corner of a newspaper and turned it into a place where six hundred authors work. I think it is that operation, more than the naming or the global spread, that kept sudoku refining itself in Japan for a quarter of a century.

And what he pursued most stubbornly, I suspect, was having no sales pitch. Here is a man who sealed off the single biggest commercial opening — brain training — because of one letter. He failed to hold the trademark, refused to grow the company, and kept saying he had no idea what makes a hit. That looks less like a lack of appetite than like a posture of handing meaning over to the solver. The author holds the answer; the solver decides why it was fun. His line about entertainment rather than education reads, to me, as a declaration of that transfer.

Closing — where to start

If you want to understand Kaji Maki, solve one sudoku on paper without timing yourself. What he meant by "the solving process, not the solved result," and by "easy entrance, hard exit," is verifiable while your pencil is moving. If you have room for more, try Slitherlink or Kakuro, also from Nikoli. The depth of the pool he called "six hundred authors" shows up as a difference in feel from puzzle to puzzle.

The closest neighbour on this site is probably Imabayashi Hiroyuki ↗ (Sokoban). If you want to think about Japanese puzzle culture as an accumulating system rather than a single invention, read the two together. And if the tension between computer generation and human authorship interests you, the pieces on Alan Hazelden ↗ and Patrick Traynor ↗ show how present-day puzzle authors answer the same question.

Sources

Primary sources consulted for this article (text verified in all cases):

・David McNeill, "Kaji Maki: First he gave us sudoku" (The Independent, 2 May 2007; revised and expanded at The Asia-Pacific Journal: Japan Focus) ↗

・"Sudoku singularity by puzzle master Maki Kaji" (iNTOUCH, January 2010; reprinted by Tokyo Reporter, 4 Feb 2010) ↗

・Nikoli, "Why hand made" — Maki Kaji, "Choose wisely" (with Nobuhiko Kanamoto, "A well-made Sudoku is a pleasure to solve") ↗

・J-Collabo, "#10 Maki Kaji" interview, June 2012 ↗

・Jonetsu-Shacho, "Nikoli Co., Ltd. President Maki Kaji," June 2012 (Japanese, first-person) ↗

・KAJI Maki, "Sudoku of the World and the Originator's Joy," Nikkei "Bunka" column, 25 Aug 2014 (English translation, Japan Policy Forum, 28 May 2015) ↗

・nippon.com, "Remembering Kaji Maki, the 'Father of Sūdoku'," 2021 (interview with Gotō Yoshibumi of the Japan Sūdoku Association; cited as third-party testimony, not Kaji's own words) ↗