An almighty crash heralded the sudden arrival of the Bionis and the Mechonis to this world, for the two titans were locked in a timeless battle. Once the dust had settled, only their corpses remained. Now, the Bionis' enormous body, covered in lush plains, is home to a developed civilisation, the Homs. But life on Bionis was not destined to flourish forever. One day, a horde of mechanical life forms from the Mechonis launched an all-out attack on the inhabitants of Bionis. The Homs' only remaining hope is a legendary sword, Monado, said to be a gift from the titan itself. Unfortunately, whosoever wields the sword must endure a great toll on their body…