The world is not what it seems. Humanity strives forward in the twenty-first century, oblivious to the truth behind the curtain. Magic and mysteries are real, for among the humans are the magi and their Mage's Association, their Holy Church, their Atlas Foundation and their secret pacts. Beasts of incredible power roam in the shadows: vampires, demons, spiritual entities and youkai. Chief among them the Dead Apostle Ancestors and the True Ancestor. The world itself, Gaia, is conscious, and even the other planets have powerful beings called TYPES looming overhead. Meanwhile the heroes of the past linger on as powerful spirits that can be summoned by magi, like King Arthur and Alexander the Great. Despite the turmoil and chaos, humanity knows none of these secrets. Most are at best food for the beasts, or bystanders for the magi.
There exists in this world magic and miracles both. Where magic is commonly known as magecraft or thaumaturgy, miracles are known as True Magic. There was a time, the Age of the Gods, when magecraft was close to True Magic, but since then, only five True Magics remain, and of those, one is officially dead, another lingers on without an user, another is inaccessible, and another yet is practiced by an old, crippled man who is as capricious as he is absent. The Fifth True Magic is in the hands of a seemingly irresponsible teenager whose propensity for destructive displays deeply worries the magi.
It's in such a world that heroes rise to defy the odds and keep the shadows at bay. In Misaki City, Tohno Shiki and Arcueid Brunestud bravely fought off the Dead Apostle Ancestor, Nrvnqsr Chaos, and later, with the help of Sion Eltnam, Night of Wallachia as well. And when Aozaki Aoko boredly decided to bring the TATARI back as a familiar, she too was unmasked and wandered off.
Meanwhile, Fuyuki City is recovering from the Fifth Heaven's Feel, with the sole survivors Emiya Shirou, Tohsaka Rin, Matou Sakura and the Servant Rider trying to return to a normal way of life.
Truly this is a world where anything could be possible, and where the shadows are as varied as the heroes who oppose them.