What is "yukigassen"

n. A Japanese game, played on a court by two teams of seven players, in which players are eliminated when hit with snowballs.

is a snowball fighting-competition from Japan. Today there are annual tournaments in Sobetsu, Hokkaidō in Japan, Kemijärvi in Finland, Vardø in Norway, Mount Buller, Victoria in Australia, Luleå in Sweden, Anchorage in Alaska, and Jasper, Alberta and Saskatoon, Saskatchewan in Canada.

The word Yukigassen consists of the Japanese words yuki ( snow) and kassen (battle). Hence Yukigassen means snow battle.