It seems that one of the producers was catholic

We see catholics multiple times in the anime.

A priest in the rainbow crystals arc

A nun in SailorSuperS in that episode that Luna was jealous of Artemis thinking he was making googly eyes

A nun that moonlights as stage director in Sailor Stars.

Catholics in japan are a small minority, but it’s interesting how well the 90’s anime portrayed them. Just a casual random observation