A man who took his own life after much anguish reincarnates into the RPG he used to play extensively, "Maken-densetsu," as D, a lowly minion of a mob character who dies in the early stages!? Lamenting his fate of dying before even his name, "Dietfried," is revealed, he meets a younger sister who never appeared in the game's story. Determined to protect his cute sister, Ria, D decides to resist a scenario that is too harsh for a low-level grunt. Using his knowledge from his past life to train his allies and using his game knowledge to unexpectedly awaken his own healing magic!! And so, the rebellion from the very bottom begins to slowly shatter the original scenario…!?