A fan theory implies that Eiichiro Oda's best kept secret, the treasure in One Piece, may be so simplistic that it may not be liked by many fans.

One Piece has finally entered its final saga, and yet the titular treasure is nowhere to be seen. Eiichiro Oda has kept One Piece a closely guarded secret, and no one has been able to figure out exactly what the treasure might be. Several theories, such as a literal treasure, a nuclear weapon, or Bink's skull, have come up, but all are still unconfirmed.

However, a fan theory claims that One Piece may be more than just a material treasure. It thoroughly examines the themes of One Piece before coming to a conclusion that may be frowned upon by many fans.

The fan theory claims that the theme of laughter and joy in One Piece is dominant, and therefore the treasure may be of the same nature. The themes are not only symbolic, but they can also be manifested in a literal sense via the One Piece treasure.