I didn't know such a thing existed. It seems all the fun takes place in Hokkaido.
Int'l snowball fight tournament begins in Hokkaido
An annual international snowball fight tournament began Saturday in the Hokkaido town of Sobetsu, attracting 1,900 snowball-fighters in 190 teams. The 15th Annual Mt Showa Shinzan International Yukigassen (snowball fight) contest is being held until Sunday at the foot of the Showa Shinzan mountain, located south of Lake Toya. The participants include people from 14 foreign countries, including Norway, Britain, the Netherlands, Germany, and Russia. Most of them are residents of Hokkaido.
The matches are based on snowball fighting rules formulated in 1988 by residents of Sobetsu and later adopted by the Japan Yukigassen Federation, an organization set up in 1991 to promote snowball fights as a new winter sport.
I had a snow-ball fight recently with my kids and husband. It was about 8.15 am. before school started and it was freshly fallen snow, who can resist???? hehe
Heh, I like that idea. Maybe have everyone wear say white snow-suits and each team use a different colored dye for their snowballs so as to easily identify when a "hit" has been scored and by whom (ala paintball somewhat). Fun fun!