In the tranquil town of Sakuranomori, a circle of young friends prepares to see one of their own off. Because of his parents' business arrangements, Sana Hidaka is forced to leave his quiet childhood home for the bustling city of Tokyo. Although it hurts him, he must part with his dear friends—the gentle Aoi Oribe, the lively Wakatsuki twins, Shuri and Shuusuke, and the bright and cheerful Nanaka Yatsushiro. Yet, despite his reluctance to leave them, he holds the belief that regardless of the distance between them, they will always hold dear the memories of their friendship. Five years later, Sana, now a 16-year-old high school student, comes back to his hometown hoping to reclaim his former life. However, he soon discovers that while his town may not have changed significantly, the friends he left behind are no longer who they were. Disturbing shadows hang over Sakuranomori as his friends keep new secrets and carry burdens that endanger the bonds they once shared.