An orphaned girl named Riko lives in the Belchero Orphanage in the town of Orth. The town surrounds a strange, giant hole descending deep into the earth, which is known as the Abyss. The Abyss harbors artifacts and remnants of civilizations long gone, and is, therefore, a popular hunting spot for so-called Cave Raiders, who undertake arduous and dangerous descents into the mist-filled pit to recover whatever relics they can find. Returning from the Abyss can be dangerous