Three people suffocating under the weight of everyday expectation meet a woman who grants exactly what they asked for, twisted into something they can't refuse. Mumako doesn't judge, she just listens, smiles, and lets the transformation speak for itself. The real horror isn't the body horror; it's recognizing yourself in every protagonist's desperation, watching them choose damnation over one more day of pretending to be normal.

A mysterious figure named Mumako appears in the lives of three ordinary people, each suffocating under the weight of everyday expectations. Mumako grants them their wishes, but in ways that twist desire into horror. Told as three separate stories with three separate protagonists, this horror OVA follows each lead as a wish is answered with a grotesque bodily transformation. Each person's new form is then found by the very figure whose pressure drove them to it. The tales are titled Castle, Transformation and Slough, names that hint at what each character becomes.