In a medieval fantasy world, a bizarre demon known as the Chin Chin Devil possesses the strange ability to fire a "penis beam" that causes female victims to grow male genitalia. The story follows Anne, a female adventurer who is hit by this beam during an encounter with the demon. Suddenly finding herself with male anatomy, Anne is filled with anger and a thirst for revenge, determined to track down the Chin Chin Devil to make it reverse the effect. She sets out on this quest accompanied by her male adventurer companion.

The narrative blends fantasy action with raunchy comedy, focusing on Anne's struggles to adapt to her unexpected new condition while pursuing her target. Throughout her journey, she encounters a variety of bizarre situations stemming from the demon's strange curse, which has also affected other females along the way. The manga, created by Fumio Kubota, is serialized through Kodanshas Comic Days web portal. The central narrative arc revolves around Anne's pursuit of the Chin Chin Devil across the fantasy landscape, with revenge and the search for a cure driving the plot forward.