The old and alone develop an emotional attachment that deepens over time to Aibo, Sony's robot dog, he says. That relationship will get even more complex with Qrio, a humanoid robot under development.

"He starts asleep, but he has emotional potential," Muto said of Aibo, which retails for about $2,000. "For someone with a strong emotional attachment, he will show happiness."

Honda and Toyota don't stress the emotions. But as Japan ages, they are also pouring money into developing a humanoid robot that can walk, talk, play music, answer questions or use the Internet.

In two years, Japan's population will begin a long decline even as life expectancy grows into the 80s. Willing or not, there are fewer young people prepared to care for an aging parent or grandparent. And Japan isn't keen on immigrant caregivers.

"Anybody who thinks they are going to get emotional love from a mechanical thing more than they would from a real dog -- that's the stuff of Hollywood movies, not real life," said David Anderson, a Dallas robot maker who works as a systems analyst at Southern Methodist University's Department of Geological Sciences.

Anderson's robots can sense obstacles, balance themselves and navigate over irregular surfaces. They're wheeled machines that look like NASA planet crawlers.

"We want machines within the house that can do something for us," he said. "If a robot has four legs and four arms ... it's uncomfortable for people. Nobody will buy it."

Honda has worked for 20 years on a robot named Asimo (a name that honors science-fiction writer Isaac Asimov). The latest iterations walk and run, dance, climb steps and navigate with the help of cameras and sensors.

"A humanoid robot doesn't really win technically," Anderson said. "But the one place they do win is coolness. They hands-down win the coolness race."

Sony's Qrio (pronounced "curio") is a little guy, 30 inches tall. He can talk in Japanese, walk and get back up if he's knocked over and throw out the first pitch at a baseball game. But he's not for sale, and it's not clear when he'll reach the market.

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