Blue Archive The Animation

Kivotos is a huge academic city made up of thousands of schools. Here, scuffles between students with guns in hand have become a daily occurrence. Amidst this, Abydos High School, which is covered in sand, is on the verge of closure. Five students from the "Task Committee" struggle to escape the situation. The story begins to move when they meet an "adult" called "Sensei."

Synopsis from Anime News Network