—— INTRODUCTION —— From a young age, Shadow Kagenou, rather than aspiring to be a hero or villain, admired the "shadow powerhouses" who secretly aided heroes. He lived a low-profile life at school while secretly training to become the strongest shadow powerhouse. Eventually, seeking an unknown power that could surpass even nuclear weapons, he embarked on harsh training. However, during his final summer in high school, he saw a hallucination on his way back from training and was hit by a truck, resulting in his death. He was then reincarnated into a magical other world as Cid Kagenou, the son of a Baron. For ten years after his reincarnation, Cid continued to hide his abilities and train in secret, just as he had before. One day, while eliminating a bandit group as part of his training and fund-raising, he found a mass of flesh possessed by a demon. After performing a magic experiment on it, the demon possession was cured, and the flesh transformed into a beautiful elven girl. To convince the elf, who said she wanted to repay her debt, Cid named her Alpha and made her his subordinate. He then fabricated a story about "crushing the Diabolos Cult, which aims to revive the demon Diabolos from fairy tales!" and established the shadow organization, Shadow Garden. However, the series of events that Cid had only imagined turned out to be "truth born from lies." The demon Diabolos and the cult actually existed. Thus, Shadow, unaware of the situation, finds himself and Shadow Garden embroiled in a battle against the Diabolos Cult.