Neuroi are fictional entities from the anime and manga series Strike Witches. They are depicted as mysterious, flying, and hostile creatures that attack humanity, primarily during an alternate version of World War II. The Neuroi are characterized by their mechanical appearance and ability to use powerful energy-based attacks. In the series, a group of young women known as Witches are recruited to combat the Neuroi. These Witches possess magical abilities and fly using special equipment called Striker Units. The conflict between the Witches and the Neuroi serves as a central theme, highlighting themes of bravery and sacrifice.