Naoto Fukuda's home in Yokohama resembles a toy store. An array of Pocket Monster (Pokemon) figures and trading cards, videogames and plastic superheroes overwhelm the second-grader's bedroom, spilling over into the rest of the apartment. The boy does things outdoors with friends, like picking up frogs and jumping rope. But his obsession is videogaming. He spends at least an hour each day in his small tatami-mat room playing Legend of Zelda on his Nintendo64 machine, and he's getting ready to plunk down $50 for a new game, Banjo Kazooie. Although teenage girls dominate the attention of Japan's trend-watchers, elementary-school boys like Naoto are no slackers as power shoppers. While older girls spend to imitate women, boys do it just to enjoy being young. By setting game trends for smaller kids, these boys are leaders of the children's world, says Hideo Takayama, president of the Children's Research Institute in Tokyo. Digital boys like Naoto are also helping prop up Japan's stagnant economy, as they and their parents buy cool stuff like videogames, the $6.3 billion pillar of the entertainment industry. Pocket Monsters are among the bestsellers. When the creatures first appeared in a 1996 game for Nintendo's hand-held player, the mainstream media paid little attention. But editors at the monthly Corocoro Comic gambled that they would become a mega-hit, based on the phenomenal response to Corocoro's Pokemon comic, which derives from the Pocket Monster game. The editors adapted the concept for TV animation in 1997, and the Pokemon boom began. Now it's popular in Asia and in the U.S. There are 10 Pokemon videogames, plus trading cards, a pinball game and items ranging from clothes to snackfoods. Even curry sales went up with Pokemon packaging, says Hironobu Sawake, game-industry analyst at ABN AMRO Securities in Tokyo. Marketing for school kids is becoming important. Kids' purchasing power seems likely to remain robust. Japan's birthrate has declined by half over the past three decades, but parents are spending more than ever on toys for their children--and themselves. Naoto's house is filled with hundreds of small Ultraman and other superhero figures. They're not mine, the boy says, they're my dad's. His father, post-office worker Minoru Fukuda, 34, collects and trades them. (He couldn't have the toys he liked when he was a child, and now that he's got money, he liberally buys them, says Fukuda's wife, Chiharu.) When palm-sized plastic cars became popular a few years ago, boys and dads often assembled and operated the battery-powered toys together. Some animation and games have more grown-up fans than kids. Comic books originally for youngsters, like Weekly Boys Jump, have become favorites among youthful salaried men on their commuter runs. Many games were made for both kids and adults, says Nintendo spokesman Yasuhiro Minagawa, but most have become only for adults. With a circulation of 1.6 million--two out of every five elementary-school boys--Corocoro Comic has become a bible for kids like Naoto. The thick, $4.20 magazine carries comics and full-color reports on toys and videogames. Naoto faithfully absorbs the magazine's contents, watches the TV programs and animations linked to the magazine and plays with the related games and toys. The magazine, its editor-in-chief argues, helps fill a void for kids who, once upon a time, tended to seek direction from a boys' clique leader, or gaki daisho (literally, kids' boss). This magazine has become the gaki daisho of the information age, says Takashi Miura. Kids can find what's trendy in this magazine, and manufacturers can find what the kids like. So what's the next big thing? Kindergarteners were behind Three Dango Brothers, a catchy hit song about three rice-cake balls. But after selling what music-marketing firm Oricon estimated at 2.6 million CDs in one month, the song's popularity is down. Boys can be fickle. What's next? Miura wants to help popularize an assemble-it-yourself robot. And computers, he says, will soon be a boom market. Can seven-year-olds like Naoto afford a PC? Perhaps. He has $1,700 sitting in a bank account: like their parents, Japanese kids are great savers.