Diane the Knight, is the fleet admiral of the Marines, succeeding Tosei — operating under the admiral alias Aoshi prior to her appointment — and preceding Napoleon. She also works as an Instructor training promising young talent at the Entaku Dojo.
She is the daughter of the former Empress of Amazon Lily, Hera and an unknown famous Marine. Her surreal abilities and unquestionable beauty had many to believe she'd be the next to inherit the throne. However, she chose to leave behind her home and champion for her idea of peace, joining the Marines and fighting for justice and security in this pirate filled world.
Decades ago, she sought to master swordsmanship in order to better handle the many enemies she'd face in her mission for peace. During her expedition to Wano Country, she operated under the alias Heiwa where she studied samurai culture and swordsmanship which in turn motivated her to develop Kendō. This feat along with her unmatched skill with a sword earned her the epithet, Strongest Swordsmen in the World.