Baseball coach Hoshiyama offers a chance to turn professional to Katsumi Kunimasa, a star member of the student squad that won the summer tournament. The young girl becomes a star pitcher for the Chunchi Dragons (conveniently, the team her father owns), and, after a year of triumphs, she leads them to victory in the national championships at the legendary Koshien Stadium. Based on the manga by Noriko Umeda, this anime may be compared to the other girl-playing baseball story "Song of the Baseball Enthusiasts".
The Dragons team members are all based on the real-life team, though their opponents are fictional. At the time, the real-life Hoshiyama was a commentator, but fact was eventually true to fiction and he became the manager for the real-life Dragons.
(Source: The Anime Encyclopedia)