Sumo is a Japanese style of wrestling and Japan's nation sport. The sport is probably 1,500 years old. In ancient times, the matches were dedicated to the gods with prayers for a good harvest. Even today , the wrestling match is accompanied by a traditional ceremony. The contest beings after a series of rituals are performed. Students train at the age of thirteen. Some of the wrestlers weigh around 265 kg. It involves a lot of physical hardship.