TOKYO (Reuters) - With straps loaded with tamagotchis around their necks, siblings Takumi and Ayaka Mochizuki traveled an hour to a Tokyo store so their virtual pets could interact with a giant tamagotchi that was on tour. "I love feeding my tamagotchi," said Takumi, 5, looking disappointed because he didn't have enough virtual money to buy anything for his "3-year-old" pet at the royal market, which is accessible only via the giant tamagotchi. "I really messed up," he said. Ten years after the small egg-shaped devices first became a global fad, the digital pets have found homes again with a new generation of young children, who peer into the tiny screens several times a day to feed them, play with them and clean them. Unlike the original, which suddenly disappeared after a brief run, Japanese toymaker Bandai Co., a unit of Namco Bandai Holdings Inc., is hoping a richer world of characters and cautious marketing will give it the staying power that its creators had always envisioned. "We've always wanted to try to revive the tamagotchi because the craze ended so fast," said Takeiuchi Hongo, Bandai's 51-year-old chief tamagotchi officer, admitting that the company was caught off guard when the toy became a sudden phenomenon in the 1990s, particularly among high school girls and young women. The latest versions in Japan, launched in 2004 and priced at about $25, come with communications capabilities so tamagotchis can meet each other and play games through an infrared sensor. The pets can grow into adults that hold down jobs and even get married to someone else's tamagotchi. Once the couple has babies -- always twins so each owner gets a baby -- the parents disappear to Planet Tamagotchi, which the children can visit via a personal computer. A badly brought up tamagotchi pet could turn into a snake or a thief, but a diligent owner can raise up to 999 generations. The company's toy unit expects operating profit in the last business year to March to jump 25.8 percent to about $136 million from a year earlier on a 7.4 percent increase in sales to about $1.5 billion, helped by the popularity of the tamagotchi. Two years after its debut, the second tamagotchi series topped sales of 20 million units worldwide this month. Although that is half the original tamagotchi's sales of 40 million units, Hongo considers the current business to be more stable and consistent. Hongo readily admits that Bandai was ill-prepared to handle the explosive demand when the traditional Japanese company of fewer than 1,000 employees launched the tamagotchi in 1996, based on an idea by an executive with an insatiable love for pets. The toy meant for young children was sought after so much that employees were banned from carrying bags with a Bandai logo for fear of theft. What started as a simple idea for a portable virtual pet turned into a cultural icon of the digital age as countries like China and the Philippines condemned the toy as anti-social and schools around the world banned them. Bandai couldn't make enough tamagotchis to meet demand, and by the time they had the capacity to do so, the boom was over. After a roller-coaster ride, the company ended up with excessive inventory and took a special loss in the business year ended March 1999 as it was forced to restructure. "We know we can't make the same mistake twice," said Hongo, who now has two small children of his own. "We had no strategy back then." To demonstrate its resolve and its intention to make tamagotchi a permanent fixture, Bandai named Hongo chief tamagotchi officer in 2004 and conducted extensive market research before relaunch. The company has avoided splashy advertising, choosing instead to work with publishers on children's magazine articles featuring tamagotchi. It also carefully paced out launches of new versions and related products as it created a world around the characters. Bandai's tamagotchi game for Nintendo Co. Ltd.'s DS portable game machine was the first game created by a company other than Nintendo to sell a million copies in Japan, and sales of a U.S. version showed a solid start. Bandai also offers a tamagotchi mobile phone game and has plans to begin selling a co-branded tamagotchi phone aimed at children with wireless phone company Willcom Inc., a joint venture between U.S. firm Carlyle Group and Japan's Kyocera Corp. According to Yano Research Institute, the electronic toys and girls' toys segments in Japan are expected to grow slightly in the business year ended March, due almost entirely to tamagotchi-related sales, even though the overall industry is expected to decline a bit to about $8 billion. "The girls' toys category is traditionally a tough market because girls have so many interests beyond toys, but the market is being lifted again by innovative products in large part due to the influence of the tamagotchi," said Rumiko Onuki, a children's market analyst at Yano Research Institute.