In a secret facility ruled by a sinister organization, only girls respond to the mysterious “growth sound.”
Captured during an infiltration mission, the girl should have weakened under confinement—yet her body reacts in the opposite way. Heat swells within her, energy gathers in her limbs, and each day she awakens taller, stronger, and increasingly impossible to restrain.

The tighter they bind her, the more violently she grows.
The more they try to break her, the more her body hardens and expands.