In the steampunk fantasy desert city of Leoure, a young and naive noble named Yote embarks on the first real journey of his life. Sheltered and educated but ignorant of the world's harsh realities, he is quickly robbed and fatally stabbed in the city's slums. Just as death seems certain, a mysterious and brilliant inventor saves him by transferring his mind into a hastily constructed cyborg body. This new mechanical form will keep him alive for only a year or two at most, and its crude design leaves him dependent on others for everything from maintenance to basic movement.

Rather than despair, Yote sees this as a chance to escape his former gilded cage and start his existence anew from zero. To fully live, however, he needs to regain his humanity. The only beings rumored to possess the magic necessary for such a miracle are the legendary sirens. Unable to travel or care for himself, Yote hires Doga, a strong-willed, resourceful, and fiercely independent street orphan who knows every dangerous corner of Leoure. For Doga, this quest is an irresistible opportunity to finally break free from her confined life and see the vast world beyond the desert. Together, the cyborg aristocrat and the cunning orphan set off on a hazardous road trip, one searching for a way to become human again, and the other searching for the freedom and adventure she has always dreamed of.