There's a new cultural infiltration by way of Japan, and this one's name is Yu-Gi-Oh! Haven't noticed yet? Stuck in the bygone era of Pokemon? Time to learn about a young animated hero named Yugi.

Yugi started life as a comic-book hero before he jumped the Pacific Ocean into American consciousness. His TV show airs on the WB network. And his card game has youngsters, teens and even some adults regularly duking it out at home and at officially sanctioned weekly tournaments.

Only time and the uncertain nature of kid-driven fads will tell if Yu-Gi-Oh! (say: YEW-ghee-oh) -- which roughly translates to King of Games in English -- will become a phenomena on the order of Pokemon. It certainly has all the ingredients.

Willie Tierney's sons, Dallas and Jean-Luc, got hooked watching the animated TV show last fall. They were among the first in line in March when the American version of the card game arrived in the Kansas City area. That was OK with Tierney, who actually liked the game himself. Plus, he had a collector's habit going back to his baseball-card days.

"It started out as an incentive for my boys to do their chores," Tierney said. "It kind of escalated from there."

Escalate is right. Once players have the $10 starter deck of 50 cards, they want to improve their decks via "booster" sets, $3 for nine more cards. The latest of three booster sets, called Magic Ruler, was issued earlier this month.

And then there are the tournaments. Mary Mancera, spokesperson for the Upper Deck Co. in Carlsbad, Calif., which distributes the American version of the game, said nearly 800 hobby and collector stores around the country signed up to take part in their tournament program.

About 46,000 players have put their names on tournament rosters around the country, with about 1,000 added every day.

Mancera said the company is privately held and doesn't release sales figures on the card game. However, the Kids WB show recently ranked No. 1 in its time slot Saturday morning for youngsters 6 to 11 and 9 to 14.

That's a big deal, said Al Kahn, chairman of 4Kids Entertainment in New York, since the show drives the game and interest in other Yu-Gi-Oh! products. Kahn's company decides what products have tie-ins with Yu-Gi-Oh!

"The show talks about the game," Kahn said. "So when you watch the show, the first thing you want to do is go out and buy the cards and play the game yourself."

While a home video was just released this week, other products have been available for several months, including action figures, T-shirts, puzzles and other games that play off the TV storyline and characters.

Plenty of Yu-Gi-Oh! players are in the first- to sixth-grade set, but anecdotal evidence suggests fans track a little older than they did for Pokemon. In the Kansas City area, tournaments attract elementary schoolers but also 20-somethings to 40-somethings.

Nick Goodner, 20, participates in Yu-Gi-Oh! tournaments at Action Sports Cards in Antioch Shopping Center. He freely admitted he got started watching the TV show and was easily drawn to the card game.

"It's Japanese anime, and I've always been into that," he said. "I have a sweet spot for card games, whatever they might be."

The tournaments are a way to meet new people and to find new challengers, Goodner said, although some stiff competition can come in small packages.

"There's nothing worse than a 5-year-old beating you because you did something stupid," he said.

As yet, the phenomenon in the United States is far from the craze in its home country. More than 3.5 billion cards have been issued in Japan since 1996. A tournament a few years ago drew 55,000 children and parents -- and riot police when the thing got out of hand.

Understandably, parents buying cards for youngsters might balk at the whole enterprise, especially those who've packed away shoeboxes full of idle Pokemon cards.

"You do hear that," said Jim Mears, owner of Action Sports Cards. "But this is the type of game you dream your kids will play. It takes strategy. It takes reading. It takes math. This is something kids should hate."

In a game, players pit their decks against each other. Each player starts with 8,000 "life points" and tries to reduce the other player's points to zero.

The cards depict monsters and other figures and have value and powers singly or in combination with other cards. There are common cards, rare cards and even rarer cards. (Every booster pack contains a rare card.)

If a player's deck lacks oomph, Mears said, he or she will go looking for more powerful cards. Booster packs help, and individual cards can be had -- for a price. A special card like "Blue Eyes White Dragon" can cost $30.

Mears said Yu-Gi-Oh! seems to be building faster than Pokemon did. One reason may be that youngsters familiar with Pokemon find it easier to pick up the Yu-Gi-Oh! rules.

At the Tierney household, everybody plays. The boys even got their mom, Brenda, into the game. Ten-year-old Jean-Luc (the family likes "Star-Trek," too) said his favorite card is Blue Eyes White Dragon. He said it doesn't bother him to lose a match.

And lest adults over-analyze the allure of the game, Jean-Luc puts it simply: "It's fun."