Fate/KOHA-ACE

The Imperial Capital Holy Grail Strange Story is a divergent Holy Grail War set shortly after the Third Holy Grail War in which Archer won the battle. The Imperial Japanese Army won the war and created a new bomb that used the Holy Grail as its core. Called the "81st Holy Grail Bomb", it is a special weapon designed to protect Japan against its enemies near the end of World War II. With an enemy from the German Third Reich’s magi division, it has become a Holy Grail War hidden in history.