By Charles Scanlon BBC correspondent in Tokyo

It was popular in Japan for more than 1,000 years, but in recent decades the ancient board game of Go went into sad decline.

Some 80% of regular players were over 60 and the numbers were dwindling.

You really have to use your brain to play Go, not like computer games

Seiya Kitabatake, nine-year-old player

But everything changed when a children's comic featured a story about a boy inspired to take up the game.

It is now a craze for youngsters that is beginning to rival computer games.

The old folks used to have it all their own way but now their dominance is under threat with youthful challengers infiltrating clubs across Japan.

Youth revival

An age-old game of territorial expansion using simple black and white counters, Go was seen as a game for grandfathers but now it is enjoying a remarkable revival.

Like many nine-year-olds, Seiya Kitabatake is fond of his video games.

Parents are happy that their children are playing Go instead of video games

But the computer console now has competition - a board game invented in China 4,000 years ago.

"You really have to use your brain to play Go, not like computer games," Seiya said.

"You need a good strategy to win."

It all began when a popular comic introduced a story about the game.

The spirit of an ancient master helped a young boy overcome his problems.

And when an animated cartoon was released last year, tens of thousands of children started signing up for classes.

On the first day of the school holidays, Seiya is ready for a marathon session.

Patience and courtesy

It is a complex and absorbing game with endless variations.

In the land of Pokemon and comics, the craze for an ancient boardgame is as welcome as it is surprising.

It really used to be an old person's game - it's amazing how much the kids know about it

Yukari Umezawa, National Go Association

Parents worry that videogames lead to irritability and a short attention span.

Go, by contrast, is seem as promoting the traditional Japanese virtues of patience and courtesy.

Yukari Umezawa has star status with the young enthusiasts, for she is the technical adviser for the cartoon and helps promote the game on behalf of the National Go Association.

"It's extraordinary how many children sign up for classes these days," she said.

"It really used to be an old person's game - it's amazing how much the kids know about it.

"They already know a lot of the technical terms before they turn up."

Even children under the age of seven can take a masterclass, and advocates say the game helps brain development and creativity.

And perhaps in a few weeks, these children could be giving their grandparents a run for their money.