Kin-Ball is a Canadian sport invented in 1987. The sport is especially popular in Canada and Japan, but is slowly gaining ground in new countries, and is currently played in more than 30 countries.
The ball that is played with - the Kin-Ball - is 1.22 cm in diameter and weighs just under a kg. Three teams, each with four players, play against each other on a square court. Here, for each team, it's about serving to one of the opposing teams where the ball has to hit the ground to get points. If the ball hits the ground, two of the teams get points.
Kin-Ball is usually played indoors as wind can make it difficult to complete the game. If played outside, you therefore use a smaller and slightly heavier ball.