Mahou Shoujo Lyrical Nanoha EXCEEDS: Gun Blaze Vengeance

Thirty years ago, unknown invasive lifeforms nearly brought the world to an end. Humanity has lived in an unstable balance with them ever since, while the United Nations organization EXCEEDS investigates and fights threats caused by the creatures before they can grow into new disasters.

On a remote island in the nation of Mizuho, Shiina Kuze works as a hunter exterminating invasive species and wants nothing more than a quiet life with her younger sister Setsuna, her only remaining family. An unexpected incident destroys that routine and draws Shiina into a conflict far larger than the island, forcing her to learn why the danger is escalating and what she is willing to risk to protect the ordinary life she wanted to keep.