Jun Naruse is a young girl burdened by a
traumatic childhood memory. After accidentally revealing her father’s infidelity, which led to her parents' divorce, she was visited by a metaphorical "egg" spirit who sealed her mouth, cursing her with the inability to speak without experiencing agonizing physical pain. This self-imposed silence defines her teenage years, isolating her from peers and turning her into a ghost in her own high school. However, her life takes an unexpected turn when she is appointed to the school’s community outreach committee alongside three other social outcasts: the detached Takumi Sakagami, the former baseball star Daiki Tasaki, and the heartbroken cheerleader Natsuki Nito.The group is tasked with organizing a musical performance for the local community. Initially, Jun is terrified, but Takumi discovers that she can express her true feelings through singing. This revelation becomes the catalyst for the group’s
transformation. As they rehearse, the four students navigate the complex web of their own insecurities, unrequited loves, and hidden pasts. Takumi struggles with his lingering feelings for Natsuki, while Daiki grapples with his frustration over an injury that ended his athletic dreams. Jun, meanwhile, finds her voice—not just literally, but emotionally—as she begins to articulate her suppressed trauma and desires.The tension peaks as the premiere of their musical, "The Anthem of the Heart," approaches. Jun faces a paralyzing crisis of confidence, fearing that speaking her truth will cause her family and friends to suffer once again. The dramatic climax forces her to confront the egg spirit of her past, realizing that her silence was not a curse but a mechanism of avoidance. In a powerful, cathartic performance, Jun steps onto the stage, successfully bridging the gap between her inner world and the external reality. The musical becomes a profound testament to the power of communication, healing the wounds of the protagonists. By the time the final notes fade, the characters have evolved from isolated individuals into a unified group, having learned that while words can hurt, they are ultimately the only way to genuinely connect with others and release the burdens of the heart.