The story follows Yukihiko Tenma, a 33-year-old shy corporate worker who is suddenly transmigrated into the game "Valkyria’s Saga" after uncovering its hidden ending. Now living as Nikolai, a weak academy student with almost no talent, he realizes this world is doomed to be destroyed in the future by the “hidden final boss”—Lucia Cynburg, a genius admired by everyone. Determined to change the tragic ending, he decides to get close to Lucia and uncover the truth behind her mysterious dream.