In 2045, music exists only as a digital commodity. The MiucS app controls every note, every melody, every beat that reaches human ears. Creating or performing songs outside this system is forbidden. Seria's life follows the expected path until an impossible encounter shatters her world: she hears genuine singing, raw and alive, coming from a ghost that shouldn't exist. This spirit, a "Great Ghost" from beyond their reality, carries melodies that predate the ban, songs that feel dangerous simply because they're real. Seria faces an impossible choice. Report the ghost and maintain her safety, or risk everything to help resurrect a forbidden art form that her society has systematically erased. What begins as a supernatural mystery becomes something larger: a question about whether humanity has lost its soul in pursuing perfect, controlled, and utterly lifeless music. As Seria gets pulled deeper into this ghost's world, she discovers that some songs demand to be sung, regardless of the cost.