From his earliest memories, Minoru Kagenou has been driven by an unwavering aspiration to attain unparalleled strength. Yet, his goal is not driven by a desire for recognition but rather a need to blend into the background. By day, he masquerades as an entirely average student, while under the cover of darkness, armed with a crowbar, he fearlessly crushes local biker gangs. However, when a truck accident abruptly ends his journey, Minoru's dreams appear to be shattered. In his final moments, he despairs at his powerlessness, realizing that despite his intense training, he was ultimately bound by the limitations of his humanity.
Yet, instead of meeting his demise, Minoru awakens in another world as Cid, the second child of the noble Kagenou family, where magic is a common occurrence. Finally possessing the power he had yearned for, he adopts the name "Shadow" and establishes Shadow Garden - a group dedicated to combating the mysterious Cult of Diablos, an organization born from Cid's own imagination. However, as Shadow Garden expands in both members and influence, it becomes increasingly apparent that the once-fictitious Cult of Diablos is far more real and menacing than Cid had originally envisioned.