This film is adapted from the text adventure game "Fate/staynight" produced by TYPE-MOON. It is the Heaven's Feel route of the game, referred to as "HF" or "Sakura Route", and is the final chapter of the three animated theatrical works of the series. In the second chapter of the theatrical work, after Sakura turned black and absorbed the souls of many Servants, she was controlled by all the evil in the world and became the incarnation of the Black Holy Grail. In the end, Shirou, who knew everything, gave up becoming a partner of justice and chose to protect Sakura...