The Great War finally came to an end after four long years of conflict; fractured in two, the continent of Telesis slowly began to flourish once again. Caught up in the bloodshed was Violet Evergarden, a young girl raised for the sole purpose of decimating enemy lines. Hospitalized and maimed in a bloody skirmish during the War's final leg, she was left with only words from the person she held dearest, but with no understanding of their meaning. Recovering from her wounds, Violet starts a new life working at CH Postal Services after a falling out with her new intended guardian family. There, she witnesses by pure chance the work of an "Auto Memory Doll," amanuenses that transcribe people's thoughts and feelings into words on paper. Moved by the notion, Violet begins work as an Auto Memory Doll, a trade that will take her on an adventure, one that will reshape the lives of her clients and hopefully lead to self-discovery.

For high schooler Kei—and for at least forty-six others—immortality comes as the nastiest surprise ever. Sadly for Kei, such a feat doesn't make him a superhero. In the eyes of both the general public and governments, he's a rare specimen who needs to be hunted down and handed over to scientists to be experimented on for life—a demi-human who must die a thousand deaths for the benefit of humanity.

Takeru Narihira is a lone wolf delinquent who spends his days getting into fights, avoiding friendships, and being captivated by a mysterious girl named Tsukimiya—someone he's only ever seen in his dreams. One day, a sudden accident sends him tumbling off a cliff. When he regains consciousness, he finds himself in Denji Heian-kyou, a futuristic version of the ancient capital, where advanced technology and mysticism coexist. This world is under the protection of the legendary onmyouji, Abe no Seimei—and to Takeru's shock, Tsukimiya is real and living in this very place. Just as he begins to revel in this fated encounter, a deadly black mist known as Yamikaoru descends, bringing forth monstrous beings called Oni. In the chaos, both he and Tsukimiya are killed—only for Takeru to awaken once again in Denji Heian-kyou. Realizing he has somehow slipped through time, Takeru resolves to defy fate. To protect Tsukimiya from her doomed future, he turns to Abe no Seimei to train in the art of onmyou-jutsu. Now, as an onmyouji himself, he must fight to rewrite destiny and uncover the truth behind this strange new world.

The third film in the six-part Girls & Panzer: Saishuushou film series.