Metal Munchers are extraordinary, semi-sentient creatures bonded with humans known as Engineers. These Engineers seek out rare and valuable metal artifacts to feed their Munchers, unlocking their potential to grow stronger and transform into more advanced forms. The older and more unique the artifact-such as a 1940s car or ancient machinery-the more powerful the transformation, a process called "Reforging."

Sayako, a self-imposed recluse, has spent the last decade confined to her room, thriving in a virtual world where she makes $50k a year playing video games. With modern technology fulfilling her every need-groceries, doctor appointments, and social interaction-she's built a life that never requires her to leave home. But when a sudden blackout disrupts her carefully constructed reality, Sayako is forced to confront the outside world for the first time in years, discovering a society far different from the one she left behind.