Gregorio is the man who you come across outside of the Herzen Museum, he never moves out of the location throughout the game. He is a well-known fan of chess. Most people will compare him to Flick from Professor Layton and the Curious Village.
Gregorio wears a blue hat, glasses, blue jacket, orange sweater and dark blue trousers.
Gregorio gives the following puzzles in Professor Layton and the Diabolical Box:
"There have been many chess fans throughout history, but few love chess like Gregorio. His love for chess extends to the decor of his house, which, naturally, consists of alternating pieces of black-and-white furniture."