在这部八月的棒球甜心动画片中,故事发生在市立里滨高中内，有原翼（西田望见 配音）是刚刚升上高中的校园新鲜人，曾经，身为棒球队队长的她对甲子园怀揣着无尽的希冀，但一场意外让她在心灰意冷之中放弃了梦想。如今的高中是一个没有棒球部的学校，虽然暗地里松了一口气，但有原翼同时还感到了小小的失望，难道棒球真的是她无法割舍的梦想吗？
出生于棒球世家的傲娇大小姐东云龙（近藤玲奈 配音）、拥有魔鬼身材，个性温柔非常会照顾人的野崎夕姬（南早纪 配音）、个性活泼开朗的天然呆河北智惠（井上穗乃花 配音），在学校里，有原翼结识了这些对棒球充满了热情和兴趣的女孩子们。
When Arihara Tsubasa enters Rigahama Municipal High School and learns that it has no baseball club, she starts up the Girls' Baseball Club on her own. Drawn to the club are girls who have never played baseball before, girls who once played it but quit, and girls who are constantly tackling great challenges. The Rigahama Girls' Baseball Club races through the trials of youth, periodically clashing and quarreling, but supporting each other all the way. And so begins the hottest summer the world has ever known.
