Riki Naoe, an orphan who lost both parents as a child, was rescued from grief by a group of friends calling themselves the Little Busters, led by Kyousuke Natsume. In their final years of high school, Kyousuke proposes one last project: forming a baseball team. Riki takes on recruiting and brings in classmates like Komari Kamikita and Yuiko Kurugaya, while Kyousuke's shy but quick-tempered sister Rin rounds out the original crew chasing one more shared adventure before graduation.