What is "whistle!"

is a Japanese manga series written and illustrated by Daisuke Higuchi, which was adapted into a 39-episode anime television series, broadcast exclusively by Animax across Japan and South Korea.

The manga, which is association football-themed, was published in Japan in Shueisha's Weekly Shōnen Jump, and in English by Viz Media under the Shonen Jump label. The manga was written in homage to the 1998 and 2002 World Cup Finals tournaments which took place in France and Japan/South Korea respectively.