A college student is reincarnated as Eumiella, a villainous noblewoman in an Otome RPG world she once played. Initially unremarkable, Eumiella soon becomes a formidable hidden boss with endgame statistics that rival those of the game's heroes.

Abandoned by her parents, Eumiella's dormant gaming spirit is rekindled. She undertakes a relentless journey to level up, achieving level 99 by the time she enters the Royal Academy. Despite her desire for a peaceful, low-profile existence, the game's main character and her admirers become wary of Eumiella, suspecting her to be the infamous Demon Lord.

Her exceptional skills lead to a sequence of challenges and adventures.

The narrative unfolds of an overpoweringly strong, malevolent hidden boss who desires nothing more than peace and anonymity.