Riki Naoe, a high school boy with a condition that causes him to suddenly fall asleep, and his childhood friend Rin Natsume have just finished leading their re-formed baseball team, the Little Busters, to victory. This group was originally created on a whim by Rin’s older brother, Kyousuke, and includes Masato Inohara, Kengo Miyazawa, and later several other classmates. But the story does not end there. Strange events begin to occur: the Little Busters members drift apart, and Riki finds himself trying to gather them again, just as Kyousuke did when the group first started. Meanwhile, Rin receives mysterious letters delivered by a white cat named Lennon, instructing her to complete tasks that hint at a hidden truth.

As Riki and Rin push forward, the world around them grows increasingly unreal. Events that should have happened are erased, and the line between what is real and what is fabricated blurs. The central conflict revolves around the secret of this world: the entire experience that Riki and his friends have been living is a constructed reality, a dream created by Kyousuke to help Riki and Rin overcome their deepest emotional weaknesses. Riki suffers from the trauma of losing his parents, and Rin is crippled by shyness and fear of others. To save them, Kyousuke built a world where they could grow strong enough to face the truth.

The narrative focuses on Riki and Rin’s journey toward that strength. They must confront their own limitations and help each other survive the trials Kyousuke has set. The other Little Busters members—Komari Kamikita, Kudryavka Noumi, Yuiko Kurugaya, Haruka Saigusa, and Sasami Sasasegawa—each play a role in this process, their own struggles and bonds serving as lessons. In the end, Riki and Rin must stand alone to dismantle the dream world and rescue their friends, accepting the pain of reality in order to truly grow up. The manga adapts the Refrain route from the original visual novel by Key, tracing this emotional and psychological arc to its climactic resolution.