While carrying out a mission for the Administration Bureau, Executive Officer Fate T. Harlaown accidentally came into contact with an ancient relic.
After learning that Nanoha would suffer a devastating injury a year later, one that would nearly end her ability to fly, Fate decided to take action. She would travel to an unknown dimension and seek a way to change Nanoha's fate.
Crossover setting. The worlds confirmed so far include: Magical Girl Lyrical Nanoha, Re:Creators, Fate/stay night, Is It Wrong to Try to Pick Up Girls in a Dungeon?, KonoSuba: God's Blessing on This Wonderful World!, GATE, Negima! Magister Negi Magi, Classroom of the Elite, My Youth Romantic Comedy Is Wrong, As I Expected, Monthly Girls' Nozaki-kun, We Never Learn, and That Time I Got Reincarnated as a Slime.