The story begins with the protagonist, Narita Masayoshi, a police officer with an overly strong sense of justice, despairing at the lack of true justice in the world and taking his own life. A god, lamenting his fate, grants him the power to enact justice and reincarnates him into another world as a young girl named Themis. However, this new world is also not what Themis envisioned. It is a world where a powerful few indulge in pleasure at the expense of the weak, and the weak are trampled by the foolish majority. Disgusted by this contradiction, Themis resolves to pursue her own brand of justice.
Chapter 4 introduces a fierce battle on a cliffside. A silver-haired woman, a military commander, leads her soldiers in a charge against a human army. She is a formidable warrior, wielding a greatsword and effortlessly cutting down human soldiers, lamenting their tendency to justify their actions with noble words. During the battle, the human commander attempts to use a fire spell, intending to incinerate his own soldiers along with the enemy. Themis, witnessing this, quickly counters the spell with her own magic, demonstrating her immense power. She spares the fleeing soldiers but confronts the commander, revealing herself to be human, much to his shock.
Chapters 8 through 11 detail Narita Masayoshi's final moments in his previous life. Overwhelmed by despair, having lost his job and being branded a criminal for upholding justice, he hangs himself. He reflects on the futility of his actions and the world's indifference to his plight. As he dies, he finds himself in a celestial space before a divine being.
The god explains that Narita's death was a result of the world's imperfections and offers him a chance to be reborn in a world where he can truly enact justice. He learns that this new world is embroiled in a war between humans and a powerful Demon Lord and his demon forces. He is given the choice of appearance, gender, and name, and chooses to be reborn as Themis, a name fitting for a goddess of law and order. He is also informed that he will receive a random, powerful ability.
Upon waking in his new body, Themis finds herself in a forest near a large road. She discovers she is now a young woman with long silver hair. She tests her newfound abilities, which seem to be related to conjuring weapons and using magical attacks, inspired by manga she enjoyed in her past life. She also learns that while she can't choose her abilities, she can arrange them to some extent.
Themis encounters a group of battered soldiers, survivors of a battle against the demon forces. She is disgusted by the townspeople who jeer and throw stones at the returning soldiers, seeing it as a reflection of the same injustice she fought against in her previous life. She intervenes, defending the soldiers and challenging the townspeople's hypocrisy.
Her actions attract the attention of Freedia, a noblewoman and leader of the White Wings Knights. Freedia apologizes for the misconduct of a guard who harassed Themis and offers her a position in her knight order. However, Themis, still seeking to understand the true nature of justice in this world, declines, stating her intention to travel and witness the world for herself.
She then visits the adventurer's guild, run by Atria, a former adventurer who reveals herself to be a demon in disguise. Atria explains the war's true origins, suggesting it was initiated by human royalty's greed, and expresses her weariness of the conflict. She offers Themis guidance and resources, including a map and money, and encourages her to forge her own path.
Themis travels to a town in the demon territory, expecting a hostile environment. To her surprise, she finds a peaceful and prosperous town where demons and humans coexist harmoniously. She is welcomed by the demon guards and is offered lodging by a kind innkeeper named Martha and her daughter, Alisha. Themis decides to stay and work at the inn to earn money and gather information, realizing that she cannot simply rush towards her goal without a solid foundation. She expresses her desire to understand the truth of this world and to fight for what she believes is right, regardless of which side it is.
