In the American city of Snowfield, a new Holy Grail War is about to erupt. Such ruthless confrontations pit against each other magic experts known as magi, who ascend to the status of Master by summoning Servants—heroic spirits of the past. The winner is thought to have any one of their wishes granted. However, it appears that the organization behind the present situation has merely managed to create an imperfect copy of the Third Holy Grail War. As the unusual ritual catches the attention of the Mage's Association in London, Flatt Escardos, the young apprentice of Lord El-Melloi II—a former participant of the Fourth Holy Grail War—travels to Snowfield and, to the great dismay of his teacher, joins the ranks of the Masters. In this fake conflict where the line between Masters and Servants is blurred, the different factions will have a hard time preventing the city of Snowfield from plunging into total chaos.

Tsubasa Shiina is a 10-year-old girl who recently moved to Hokkaido to live with her father. In school, she is very quiet and unsociable with her classmates. Then one night, she witnesses a UFO crash in the forest near her home. She rushes to the scene and finds the pilot, codenamed D.D., in a barely stable condition. Also in the scene is a Maguar, a hideous alien that hatched aboard D.D.'s ship. As the Maguar is close to taking Tsubasa's life, an alien lifeform fuses with her body to form the Riberus battle armor Figure 17, which shortly destroys the alien threat. The life form takes the name Hikaru and turns into an identical twin of Tsubasa. As time passes, Tsubasa becomes more open to everyone around her, thanks to her new twin sister Hikaru. However, with Maguar eggs scattered all over Hokkaido, their ability to form Figure 17 is needed to eliminate all hatched Maguars until backup from D.D.'s home planet arrives on Earth. (Source: ANN)

A 3D computer animation about a female robot duchess named Drossel von Flügel and her guardian servant robot Gedächtnis. (Source: ANN)