"Ore-sama Kingdom DX" centers on the life of Himeka Haruna, a high school girl who unexpectedly becomes the ruler of a mysterious kingdom known as Ore-sama Kingdom. The kingdom is populated by eccentric and flamboyant individuals who refer to themselves as "Ore-samas," each embodying exaggerated self-confidence and unique quirks. Himeka, an ordinary and unassuming girl, is thrust into this bizarre world after being chosen as their queen due to her pure heart and ability to see through their grandiose facades.

The narrative unfolds as Himeka navigates her new role, balancing her responsibilities as queen with her everyday school life. The Ore-samas, despite their over-the-top personalities, rely on her to mediate their conflicts and maintain order in the kingdom. Key characters include the self-proclaimed "King of Kings" Ore-sama, who serves as her primary advisor, and other Ore-samas like the flamboyant artist, the narcissistic athlete, and the melodramatic poet. Each character brings their own brand of chaos, often leading to comedic and absurd situations.

As the story progresses, Himeka's influence begins to soften the Ore-samas' egocentric tendencies, fostering genuine connections and personal growth among them. The series blends humor, fantasy, and slice-of-life elements, exploring themes of self-discovery, leadership, and the importance of humility. Through her interactions with the Ore-samas, Himeka learns to embrace her own strengths and finds a sense of belonging in this unconventional world. The manga maintains a lighthearted tone while subtly addressing the complexities of identity and relationships.