Vatican Miracle Examiner: Black Academy

Based on the eponymous novel, the story focuses on Hiraga Josef Kou, a genius scientist, and Robert Nicholas, an archives and cryptanalysis expert. They are partners and two of the Vatican's "miracle examiners," whose job it is to travel the world and conduct investigations to verify the authenticity of claims regarding miracles.

In the Bachikan Kiseki Chousakan series:

V.1 - Kuro no Gakuen (Black Academy)
V.2 - Satan no Sabaki (Satan's Judgement)