Fathers Josef Kou Hiraga and Roberto Nicholas are Vatican Miracle Examiners who investigate the authenticity of miraculous phenomena reported from all over the world. In every seemingly sacred event lies horrors of hidden conspiracies, mysterious murders, and devil worship. In this battle of good and evil, Hiraga, a scientific and mathematical genius, and Roberto, a polymath in linguistics and classics, must work together to bring the truth to light. Will their friendship and faith endure the evils in their journey to find a true miracle?

This anime is based on a playstation game under the same title. The story is about four people who travel the desolated land of Filgaea and carve themselves a legendary story while they're at it. These adventurers are Sheyenne Rainstorm, a gunslinger who holds the legendary weapon called ARMs; Kiel Aromax, a scientist who looks like he should be carrying a sword; Roleta Oratorio the Crest Sorceress, a magic-user who uses cards called Crests to cast spells; and Mirabelle Graceland, one of the Noble Red, which are a family of vampiric creatures who live alongside human beings They also travel with cute little intelligent furry things, from the Popepi Pipepo Tribe, named Isaac and Jerusha. (Source: AniDB)