Strike Witches OVA

An alien force known as the Neuroi attacks Earth in the 1940s, causing widespread destruction. A man develops a weapon called the Striker unit, which enhances magical abilities and allows flight through mechanical leg attachments resembling witches' brooms. A group of young witches, called Strike Witches, is assembled to combat the Neuroi. The man is believed to have died in service. His daughter lives a normal life, unaware of her untapped magical potential, which she wishes to use for healing. She is abruptly taken on a mission to determine if her father is still alive and discovers his invention, considering the possibility of using it herself.