One by one the fighters strut into the Korakuen stadium hall in Tokyo, accompanied by thunderous applause.
But this is no normal wrestling match — the contenders are diminutive humanoid robots built and controlled by participants in the twice-yearly Robo-One Championships.
In the featherweight division, "Automo03-Sandan" — a robot dressed in karate gear — is no match for "Leghorn," a chicken-like robot known for its vicious "Chicken Chop" martial art moves.
"Japanese children have all been brought up watching animation and there is a lot of interest in robot battles, so this Robo-One competition is all about making this a reality," said Robo-One committee Chairman Terukazu Nishimura.
Japan's warrior robots come in all shapes. From medieval princes to cubic robots, 112 of them entered the two-day tournament. By Sunday, the final day, 45 remained standing among the heavyweights and featherweights.
In the lightweight division, South Korean robot Teakwon-V smashed his opponents with a quick jab, to the delight of his maker Jeon Young Sun, who took home the 1 million yen ($10,000) division prize.
"It is a good chance to see Japan's advanced robot technology," Jeon Young Sun, an engineer, told Reuters.
"Some people say that South Korea's technology is unsatisfactory, but I would like to show ... that South Korea's robot technology is doing really well by continuing to participate in robot competitions and walking shoulder to shoulder with Japan's teams until we develop our technology and do even better," he said.
Japan, home to 40 percent of the world's robots, provides a fertile ground for amateur programmers, who invest serious money and energy into building the ideal robot out of server motors, cameras, sensors and wires.
Many electronics companies, on the other hand, have pulled the plug on cutting-edge robots for the consumer market because of high development costs. For example, Sony Corp has decided to stop production of its Aibo dog robot.
Naoki Maru, a 41-year-old engineer and winner of the heavyweight division class, believes such reluctance gives amateurs an advantage over big corporations.
"You see a lot of technological breakthroughs in these kind of fighting robots. This competition, for example, happens twice a year, but every time we gather you witness here some incredible technological revolution in robotics," he said.
"It's just great that in this field the 'hobbyists' develop and improve their robots faster than in the corporate world," he added.
Maru's "King Kaiser" fighting robot, controlled by his 12-year-old son Kenta and 9 -year-old son Ryouma, went on to beat Jeon's 'Teakwon-V' robot in the All Class division that pits lightweights against heavyweights.
