The story revolves around a young boy named Sport Billy who is from the planet Olympus (a twin of Earth on the opposite side of the Sun) which is populated by athletic god-like beings. Billy himself has a magic size-changing gym bag - the Omni-Sack - which produces various tools as he needs them.

An American time-travel themed television series, adapted from a German comic book character created by Rolf Deyhle. Sport Billy is a humanoid alien from the planet Olympus, a Counter-Earth populated by athletic god-like beings. Billy time-travels to various periods of Earth's history to promote teamwork and sportsmanship, and to thwart the attempts of his archenemy Queen Vanda to destroy sports culture and sports history. Billy has a magic size-changing gym bag, the Omni-Sack, which produces whatever equipment he needs for each mission. The supporting cast includes Billy's employers Sportikus XI and his wife Pandusa (the rulers of Olympus who send him on missions), Billy's athletic girlfriend and co-worker Lilly, the couple's talking dog Willy, and Vanda's gnome-like henchman Sipe.—Dimos I