The Ainsworth family's goal is to save the world from evil, but their success depends on the great sacrifice Magical Girl Miyu makes for them. Her brother Shirou, however, is not willing to let the family have his sister without a fight. That’s why he doggedly searches for a way to save not only the world but also Miyu...
As Sakura drowns in the murky darkness of the sins she has committed, Shirou's vow to protect her at all costs leads him into a raging battle to put an end to the Holy Grail War. Will Shirou's wish reach Sakura even as he challenges fate itself in a desperate battle against the rising tide?