10 Years after the 4th Holy Grail War, the Emiya children become a part of the Gold Faction of masters in the Ikebukuro Holy Grail War. They must fight against the White faction with their servants. However the White faction is facing enemies within, and the overseers of this Holy Grail War have wishes of their own.

After killing Koro-Sensei, Nagisa is sold by his mother to the Yggdmillennia Clan, and is dragged into an arranged marriage and New Great Holy Grail War. To make matters worse, his best friend Karma is on the opposing faction. Will Nagisa be able to survive and keep his loved ones alive?

In the end of the Second Year of the Clone Wars, the Second World War is increasing in size once Japan bombs Pearl Harbor. Seeing an opportunity, The Confederacy of Independent Systems allies itself with the Axis Powers, forcing the Galactic republic to intervene on behalf of the Allied Powers. Which way will these wars go?