One weekend a long time ago, as I was on a train heading home after playing the ponies -- and losing -- I opened an American puzzle magazine I had with me. There was a game called "Number Place." I'm not fluent in English, so I started filling in numbers without having read the rules. It didn't take me long to solve it, but I found the game fascinating. I bought some back issues of the magazine and plugged away at the puzzles. I then began designing puzzles of my own.
In 1984, I placed one of my original puzzles in a magazine published by Nikoli, the Tokyo-based company where I serve as president. To decipher it, you had to fill empty squares with numbers from one to nine. I named the puzzle Suji wa dokushin ni kagiru (the digits are only those that are single -- or, literally, "unmarried").