KenKen, a strange little math puzzle from Japan, may conquer the world.

[film rolling] [piano key playing]

[Announcer] Four, three, two, one, KenKen.

[piano music]

So, I probably heard about KenKen five, ten years ago,

as yet another Japanese puzzle, trying to break

through to get that Sudoku position

in newspapers of the world.

I learned about KenKen through Games Magazine.

In a graduate school class at Brooklyn College.

Randomly, in maybe a airplane magazine

or a random website.

I saw the puzzle in New York Times, the online version.

I was teaching at a school upstate in New York.

And okay, fine, there's a crossword puzzle,

but here's this other, strange, little, mathy puzzle.

How does it work?

There were light lines, and dark lines,

and addition signs, and division signs.

And it had lots of numbers in it

and I was like, yeah, but I never really even tried

to do it.

[piano music]

But the time I really got into it was

when I actually met Miyamoto.

I say, he's a magician.

He's a miracle magician.

You haven't seen a person like him ever in your life.

[piano music]

[birds chirping]

I invented this puzzle in 2004.

I felt I invented the real puzzle.

In these ten years, people say puzzle, KenKen.

It's not realized now,

but it will be realized in near future.

[Interviewer] And what will be realized

in the near future?

KenKen will conquer the world.

[light music]

His classroom is very unique,

so it's called the art of teaching without teaching, right?

There was no talking allowed.

There is no question allowed.

You come into the class, say hello.

And he's like, nod, your words, they sit.

And there is a clock on the wall.

He started to hands the paper,

upside down like this, in front of the kids.

And then he goes five, four, three, two, one, start.

And then they do a KenKen.

When he's done, raise hands, he comes, check an answer.

And if it's correct, he says, [speaking foreign language]

and if it's wrong, he says, [speaking foreign language]

that's all he talks in his classroom.

[light music]

No nervous, no progress, I believe.

[Interviewer] How come?

How come?

[light music]

Every lesson, math,

baseball, martial arts,

nervous air is necessary.

I enjoy nervous air.

[suspenseful music]

Here's your last one, this is a two-word answer.

It's bridge and baseball, bridge and baseball.

Your starting letter is G, G.

[Woman] I don't play bridge.

In the eighth grade,

when I, in a class where I was supposed

to write a paper on what I wanted to do with my life,

I said I wanted to be a professional puzzle-maker.

I don't think many kids, at that age, choose puzzle-making

as a career, but that's what I wanted to do.

And that's what I went on to do with my whole life.

It's grand slam.

[Announcer] Grand slam is correct.

[Woman] Bravo.

Guys, give yourself a hand.

I'll tell you what happened.

He introduced the puzzle,

of course it takes 10 seconds to introduce,

gave me one to try, I liked it,

and I asked him for a second one.

And after I had solved that, then I asked for another.

He had brought a book with him,

so when he left, I asked him to leave the book with me.

And over the next week, I solved virtually the entire book.

I became obsessed with KenKen, right at the start.

Mind you, all the puzzles, at this point,

were handmade by Miyamoto.

And, you get in a newspaper,

and then ultimately website,

you can't do that by hand any longer,

you need a computer program.

You need to generate these things.

And luckily, that was David Levy's world,

who was the father of computer chess.

And he created this KenKen-generating machine

or algorithm,

it lived to be called the Kenerator.

[light electronic music]

Once we'd realized that there was,

there were commercial possibilities for KenKen,

it was obvious that it had to be done by a computer.

What I wanted to do with Miyamoto was

to find out how he thinks when he creates a puzzle.

It's feeling, just feeling,

like a picture.

There is a beautiful picture.

What point beautiful?

I think most people cannot explain.

Same.

[Interviewer] Can I show you two puzzles?

You might recognize this one.

Does that look familiar?

This is puzzle I made.

Of course, yes.

[Interviewer] And this one, I'm going to show you as well.

This one made by computer software.

I think they're not interesting,

so I feel nothing from this puzzle.

One of my students sometimes give me puzzles.

It looks very fine and interesting.

Every time I want to solve it as soon as possible.

Oh, that one.

This one is beautiful.

This puzzle has story.

This one doesn't have any story.

[light music]

How could just entering the numbers one through nine

in a grid make you laugh or make, make you smile?

But, there is a certain kind of playfulness.

[light music]

I'm certain I've never done a puzzle

that was made by Miyamoto

because I've never seen anything this pretty-looking.

[light music]

[Interviewer] Do you think that eventually computers will

be able to make a puzzle that is more similar

to your puzzles?

Impossible.

A machine doesn't have heart.

They cannot make Shakespeare, Beethoven, Picasso.

It's our work, it's for human beings.

Shall we KenKen?

[upbeat music]

Kenerator is an amazing piece of software.

It's never, ever had a bug.

It's never produced a puzzle that has no solution.

It's never produced a puzzle

that has more than one solution.

[upbeat music]

New York Times crossword puzzle,

please welcome back to our show, Will Shortz.

[upbeat music]

Computer-generated puzzles and the scores, doesn't match.

Do you think it matches?

I don't think it matches at all.

And Mr. Miyamoto didn't like that.

[upbeat music]

And the kids love KenKen so much,

they do it on their own.

They like it more than video games and TV.

I bet they do. I like it.

I, every morning in the car, I do at least one of them.

My little website, which was getting 300 visits a day,

I think had 30,000 visits.

And, it was massive.

Got one and two in this order,

six and one over here.

Okay, so this has to be a five.

[Man] Gotta be a six and five, seven plus four.

What's good about KenKen,

and Sodoku, and crosswords, all of those puzzles like that

is that they have grids to be filled in, empty squares.

I think there is something about human nature

that we want to fill up spaces.

And if you're a puzzle person, or almost anybody,

and you see an empty grid,

you want to put something in those spaces.

It gives a feeling of satisfaction that you don't get often

in life and that really feels good.

[Man] So, that has to be a four

because the three's over here.

[Woman] Got it.

[Man] Got it, okay.

[Woman] So it's a lot of like that kind of thing.

All right, cool.

Yeah, I felt it.

Most important thing is that every puzzle has

only one solution.

So, I will check this puzzle.

I would say he is not a man of KenKen.

He is a man of education.

He really had a interesting life, himself.

He kind of failed in lots of things.

I think he wanted to commit suicide.

He got into math teaching because it was

the only job he could already get.

[light music]

He was very passionate teacher.

One time he was very close with the students, like friends,

but he didn't see the students who grow.

He didn't see the students really thrive.

He realized they have to think by themselves,

and he started to give KenKen

and use KenKen in his classroom.

And over a period of 20-odd years,

he kind of created his own kind of homegrown philosophy,

which, as he says it himself, is teaching without teaching.

And KenKen is a kind of masterpiece in getting people

to learn themselves.

[suspenseful music]

[Grader] Yeah, yeah, sure.

Now, there are many KenKen contests all over the world.

[suspenseful music]

First, I think it's very interesting.

But now, I'm bored such a competition.

[suspenseful music]

It's only a solving contest,

sooner is the winner.

Most important point is continue thinking

with high concentration.

Do not rush the answer.

Do not rush success.

[suspenseful music]

[participants cheering]

So without further adieu, here is Tetsuya Miyamoto.

Hi, everybody.

Why must we learn and to study?

For what?

It's for happy life.

Happy life, what is it?

Studying high-level university, working with good company,

like Google, and getting behind somebody, like you.

Is it always a happy life?

I don't think so.

[somber music]

When I was 14 years old, I went to low-level high school.

It bored for me, so I quit.

I started to study by myself to grow me up by myself.

It didn't work well,

and I failed.

[somber music]

And at that time, no hope for me.

I didn't have friend.

And very, very loneliness life.

And I though about suicide almost every day,

but it's the bottom of my life,

I believe.

[soft music]

In Japan, also in United States,

many young people abandon their lives themselves

to suicide.

In younger age, myself.

So, I write, I wrote this book.

[soft music]

If you think of yourself as just one by seven billion,

it can make you want to die.

But if you think of yourself as an irreplaceable one of one,

doesn't it stir just a little bit of courage?

[light music]

I always choose hard way, not easy way.

The accidents make me strong.

[soft music]

First time we met, it was 2016, July 13th.

After six weeks, we got engaged.

Next month, we married.

[light music]

Formerly, obsessive, amazingly hard-working,

but a kind of slightly reformed character

since he got married, and full of the joys of life,

and actually quite able to look at his own life

and see it as some kind of story.

So, he's quite big on the fact that there's,

these puzzles are not essentially about math or logic,

they are about life lessons.

Someone once said, about writers,

that if you've lost your interest in writing,

you've lost your interest in the world.

And I feel the same way about puzzles,

if you lose your interest in puzzles,

you've lost interested in life.

[light music]

I am an entertainer.

People call me charisma or super teacher.

No, I am an ordinary man.

I learned everything from my mistakes.

It's a very important property.

Failure is much more important than success.

[light music]