(運動会) Literally meaning "excercise meeting", undoukai are a tradition upheld by all
Japanese schools. Each year in
summer, the students train for weeks in advance, to compete in various disciplines while being cheered on by their relatives. In accordance with the group-centrism of Japanese society,
team spirit is stressed over actual athletic
competition, so there are no events which would have a single winner, instead there are only group events such as relay races.
In fact, even winning groups are not credited directly, instead the students are divided into two big teams (traditionally color-coded
red and white), and winning one event earns points for that team. In the end, the winning team receives a big trophy, and the not-winning team a slightly smaller one.
The anime series called Battle Athletes in English is originally titled 大運動会 or "big undoukai".