In the world of Gamindustri, four goddesses known as CPUs battled for supremacy in the War of the Guardians. One of the CPUs – Neptune – was defeated by the others and banished from the heavens. In her fall from grace, her memories were lost but a mysterious book reveals itself to Neptune with knowledge of all of Gamindustri’s history. Joined by Compa, IF, and the sentient book known as Histoire, Neptune embarks on an extraordinary journey across four different nations on a quest to save the entire world!