After a decade spent fighting monsters in the Shadow Labyrinth—a growing dark cloud of magic that threatens to engulf the world and destroy all life—mage Desir Herrman and his five companions finally face their last foe: the dragon of destruction Boromir Napolitan. Although the group of heroes manages to slay this formidable opponent, the tremendous amount of mana stored within the dragon's body is released in an unstoppable explosion that annihilates the rest of the world. However, instead of dying, Desir is sent back 10 years into the past with complete memories of events to come. He enrolls at Hebrion Academy, determined to put an end to the classist prejudice plaguing the magical world that will ultimately lead to the demise of humanity. Unfortunately, his struggle begins early on during the entrance exams; although he is ranked first of his group, Desir is assigned to the Beta Class, the default class for commoners. Now, Desir's next objective is to rally someone to his cause that he could not save in his previous life: the wind mage Romantica Eru. Then, Desir will have to show his worth to the Alpha Class with his newly formed party if he wants to ultimately save as many lives as possible.

When, after her sudden death, Rinko Hanasaki is reborn as Raeliana McMillan, she is not sure whether to curse her luck. Raeliana was a minor character in a novel Rinko read, and as the eldest daughter of a nouveau-riche baron, she led a carefree life until her unfortunate demise at the hands of her fiancé, Lord Francis Brooks. To avoid her destined fate, Raeliana is determined to end her engagement with Francis. However, when Francis refuses to break things off, Raeliana decides to seek help from someone of higher standing and approaches Duke Noah Wynknight—the novel's male protagonist. Using her knowledge of the plot, Raeliana captures the duke's interest by proposing a deal: she will not expose his secrets if Noah agrees to act as her fiancé. Little does she know that getting involved with a duke who only shows his true colors around her may lead to more than she bargained for.