They are a famous magus family. It is uncertain when they decided to save humanity but they continued their journey for more than 1000 years. 200 years ago, the Ainsworth sought the power of the Holy Grail and formed with two other magus family to develop the Holy Grail War and created the Class Card system afterward. They are similar in nature to the Einzbern family, seeking the Holy Grail and creating many homunculus-like servants that they call "Dolls."
Julian claims that their overall goal lies in saving the world from the degradation. His plan is through the sacrifice of Miyu Edelfelt and to transform humans into a species that can survive the environment that will eventually be produced by the world's collapse. They specialize in the magecraft Flash Air.
- Darius Ainsworth (Original head)
- Zachary Ainsworth (Previous head)
- Angelica (Eldest child, Doll)
- Julian Ainsworth (Current head)
- Erika (Youngest child)
- Beatrice Flowerchild (Doll)