Among Japan's young sumo wrestlers, 10-year-old Kyuta Kumagai stands out. At 187 pounds, Kyuta is twice the size of other children his age. He's so dominant that he wrestles, and defeats, boys five or six years older. Last year, he was crowned the under-10 world champion, beating competition from the UK and Ukraine. A shy boy of few words, Kyuta's motivation is simple. "It is fun to beat people older than me." The sport of sumo demands dedication. It's popularly regarded as Japan's national sport and goes back 1,500 years. Kyuta trains six days a week, either at his local sumo club or lifting weights. He also swims and practices track and field. It also takes food - a lot of food. On an average day, Kyuta will consume up to 4,000 calories, downing a liter of milk and copious amounts of protein. He says steak's his favorite. Kyuta's tough training regime was devised by his father, who says this is all worth it: "I don't think I'm wasting money at all. It is not easy. I have to spend a lot of time and money. But I think it is worth investing. I don't gamble. Instead, I'm betting everything on this." When it became apparent Kyuta had a special talent for sumo, his father moved the family to Fukugawa in Tokyo. The area is famous for producing wrestlers and is home to the Nominosukune Shrine, where the God of Sumo is said to reside. Now, Kyuta has his sights set on his next goal: Reaching the level of 'yokozuna' - the highest ranking in wrestling - and all the blood and sweat that will entail.