A bag of potato chips that went on sale in October 1999 is a hot item among Japanese boys in elementary and middle school. What's so special about this ordinary snack? The secret lies in the card that comes with it; the boys are buying the chips mainly to collect these cards. The cards have photographs of Kamen Rider heroes and villains printed on them. Kamen Riders, though, aren't new characters at all. They are the heroes of a television series that was aired beginning in 1971--right around the time the parents of the boys now collecting the cards were kids. In the series, a young scientist named Takeshi Hongo fights to prevent the evil plans of the secret organization Shocker to conquer the world. When Takeshi shouts "Henshin!" (transformation) with arms raised up high at the climax of each episode, he turns into Kamen Rider, a cyborg with supernatural powers. Then the hero would ride over rocky or rough places on a motorcycle and beat up monsters without using any weapons, instead using martial arts techniques like kicks and chops. Hongo has a partner, Hayato Ichimonji, who transforms himself into Kamen Rider number two to thwart Shocker's schemes. Several sequels featuring new heroes appeared after this first series, and they all became very popular. Many children at the time admired the heroic acts of the kindhearted yet strong Kamen Riders; one of their favorite activities during recess was pretending to be these cyborgs, taking poses and shouting "Henshin!" on their school playgrounds. The cards themselves aren't new, either. Kamen Rider snacks were also being sold around the time the first TV series was airing (1971 to 1973), and these came with cards, too. But some kids bought the packages just for the cards, throwing the snacks away. Adults took this up as a major educational issue, saying that these children should be more thankful for their food. The same package design is used for the new Kamen Rider chips, and each bag comes with one card, just like the first snack. There are a total of 144 different cards in the new collection--72 are reproductions of the original cards, while 72 were newly designed using old footage--and the size is 1.5 times that of the original series. If you collect two "lucky" cards, moreover, you can trade them for a Kamen Rider photo album or special book. That's another reason why these boys are busy collecting the cards. The flavor of the new snack, by the way, is plain salt. The manufacturer hopes that this time, the children will eat the potato chips without throwing them away. Photos: (Top) Each bag of Kamen Rider chips comes with one card; (above) the cards feature monsters, the heroes, or both of them in battle.