The Lowreis family faces wrongful execution for an attempted assassination of the royal family. As Linali Lowreis, the family's daughter, stands on the brink of death, she fervently prays for a second chance. Her plea is miraculously answered, and she awakens three years in the past, reunited with her deceased family members. However, this second chance comes with a heavy weight of foreknowledge: she knows that attending the School of Poltis, specifically her brother Liam's enrollment, is the catalyst for the family's destruction.

Linali is determined to alter the tragic course of history. Convinced of her superior sword-fighting abilities, she begs her father to send her to the elite academy in her brother's place. Donning male attire and adopting Liam's identity, Linali infiltrates the School of Poltis, hoping to dismantle the conspiracy against her family from within. The central conflict of the series arises from her high-stakes deception; she must navigate the dangers of noble society and the rigors of academy life while ensuring her true identity and gender remain concealed.

The narrative is grounded in a fantasy world where magic exists, and the story is driven by themes of regression, revenge, and identity. The main characters include Linali (also referred to as Lenalee in some sources), a young woman hardened by a future tragedy and determined to become her family's protector. Her twin brother, Liam, is the person she is replacing. A critical figure in this new timeline is Fasias, a member of the group led by the crown prince. Unlike in her past life, Fasias takes a liking to the disguised Linali, setting up a complicated and potentially dangerous romance between Linali, who must guard her secret at all costs, and a member of the royal circle she suspects is connected to her family's doom.

The story unfolds across several notable narrative arcs. The initial premise establishes the time-leap and the successful swap of identities. The focus then shifts to Linali's life at Poltis Academy, where she must prove herself as a student and a swordsman while avoiding exposure. A major storyline involves her complicated relationship with Fasias, a school love story complicated by deception and political intrigue. As Linali gets closer to the crown prince's circle, she begins to unravel the true scope of the conspiracy, which features well-hidden villain twists that subvert expectations. The complete series runs for 110 chapters, and after the main conclusion, the story continues into epilogue chapters that explore the long-term consequences of Linali's altered timeline.