Many of One Piece's secrets have been revealed by the Straw Hat Pirates, but despite entering what has been confirmed to be the series' final saga, numerous mysteries still remain unaddressed. Of these unanswered mysteries, a few stand out due to just how much they will undoubtedly affect the show's sizable lore.
The One Piece is arguably the most well-maintained secret in anime history. For a show named entirely after a single treasure, the iconic shonen has revealed an impressively small amount of information regarding whatever Joy Boy left on Laugh Tale.
Thanks to the Roger Pirates, fans have at least been able to see the reaction of a few characters learning the contents of the treasure. Other than this, Eiichiro Oda has thoroughly avoided the topic. Safe to say, when Monkey D. Luffy inevitably reaches Laugh Tale, One Piece will be set for the biggest reveal in anime history.