Gaucher is a character from the one-shot Rohan at the Louvre.
Gaucher had extreme caution with the work at the Louvre and the safety of people. He assigns two firefighters to accompany Rohan, as well as himself and a interpreter, for just five minutes to make sure nothing goes wrong. That's because he didn't know if there was any danger, as the area was abandoned. He also showed incredible knowledge about the Louvre's history and all its 350000 pieces of art, no matter if well known or not.
At some point in his life, Gaucher was involved in a car accident which resulted in the death of a man.
Gaucher is introduced as the responsible curator for the Department of Oriental art at the Louvre. He gives Rohan Kishibe authorization to research Nizaemon Yamamura's painting "Under the Moon", but only for five minutes and asks him to leave behind anything he has. Surprised that the Louvre had a work of an artist he never heard about in the Z-13 section, which was long ago abandoned, he accompanies Rohan along with two firefighters of the security services and the interpreter Noguchi to investigate it.
When the group finally finds the painting, one of the firefighters has his skull pierced and is sucked into the darkness of the ceiling. Gaucher is the first to notice the ghost mob attacking them and attempts to call the police, believing them to be simple thieves, but is smashed against the wall and suddenly covered by tire marks across his body. Moments before dying, Gaucher recognizes a ghost as the same person who was killed in the traffic accident and is sucked into the ceiling's darkness. His body was never found and he was considered since then as missing.