Long ago, demons fed on human souls, offering them to their ruler, Gwi-Ma. To end the terror, three women rose as demon hunters and sealed the creatures behind a magical barrier called the Honmoon. Their descendants inherited this task, each generation of hunters using their singing voices to maintain the seal, strengthening it with the dream of turning it into the Golden Honmoon, which would permanently banish demons from the human world.
In the present day, the K-pop girl group Huntr/x – Rumi, Mira, and Zoey – carries on this legacy under the mentorship of Celine, a retired hunter who raised Rumi. After finishing a successful world tour, the trio prepares to debut their new single, “Golden,” but Rumi begins to lose her voice. Only Celine knows the reason: Rumi secretly carries demon blood, marked with faint patterns that would disappear if the Honmoon turned gold.
Meanwhile, in the demon world, Gwi-Ma fumes at his followers’ repeated failures. Five demons, led by Jinu, a former human, form a rival boy band called the Saja Boys, intending to steal Huntr/x’s fans and weaken the Honmoon. Jinu trades his memories of his human life for Gwi-Ma’s promise of revenge. During the Saja Boys’ debut, Huntr/x confronts them and recognizes their demonic nature. Jinu discovers Rumi’s secret but keeps it from her friends, later meeting her in secret to reveal that demons are bound by shame and by Gwi-Ma’s voice in their minds. He confesses that centuries earlier, Gwi-Ma granted him a beautiful singing voice that lifted his family from poverty, only to damn him and destroy everything he loved.
As the Idol Awards draw near, Huntr/x rush to write a new diss track, “Takedown,” to expose their rivals, but Rumi hesitates, worried it spreads hate. She proposes to Jinu that if he helps them win and strengthen the Honmoon, he could remain in the human world. Their bond restores Rumi’s voice, but Gwi-Ma soon reminds Jinu of their bargain, threatening to return the tormenting voices if he disobeys.
At the Awards, impostor demons sabotage the group, tricking Rumi into performing “Takedown” and exposing her demon patterns. Betrayed, Mira and Zoey abandon her. As Gwi-Ma’s final plan unfolds, Rumi rejects Celine’s offer to hide her shame and instead confronts it. She interrupts the Saja Boys’ last performance with a song about self-acceptance, freeing the entranced audience. Jinu sacrifices himself to save her, and the empowered Huntr/x defeat Gwi-Ma, creating a renewed Honmoon. Fr
