At Tokyo's 12th Robo-One Grand Championship match, two-legged robots jabbed, ducked, hurled balloons and even sang in their quest to become world champ.
Twenty-five finalist robots put up their fists to knock one another out of a ring on Saturday, showing off some of the latest moves originated by children, homemakers and other robot fans in the world's biggest robot market.
Hundreds of spectators clapped as robot "Arichyon," clad in Christmas lights, sang "We wish you a Merry Christmas." They then cheered when a robot with a penguin head toppled Arichyon over with a single punch.
Japan, home to 40 percent of the world's robots, is also fertile ground for amateur programmers, who invest serious pocket money and hours into making the ideal biped out of server motors, cameras, sensors and wires.
To win the tournament and the title of the world's strongest two-legged fighting robot, contestants need to be able to keep their balance while punching and dodging blows, and get up when pushed down.
"Companies can't make money making robots like these," said Terukazu Nishimura, chairman of the Robo-One committee. "The future of robotics depends on amateurs."
The cost of developing robots has compelled electronics firms to pull the plug on cutting-edge robots targeting the consumer market. The most prominent example is Sony Corp's Aibo dog robot, discontinued last year.
Toymakers such as Takara Tomy now have entered the consumer robot market, with firms cutting development costs and simplifying design to market low-cost robots for the home.
But toys just don't cut it for true robot lovers like 40-year-old Naoki Maru. Robot hobbyists have long outpaced companies in innovation, he said.
"You cannot win the tournament without the help of a major innovation every six months," said Maru, designer of the former Robo-One champion. "You don't see that kind of speed anywhere else."