Charon, a major character in the series, is initially a shy and academically focused resident of the Jewel Palace. She enters training as a Petite Lady under the mentorship of Sapphie the Jewelpet. Before this, she aspired to be a romantic novelist, inspired by heroines from stories her older sister Eris shared during their childhood. Her initial reluctance to become a Petite Lady shifted after Sapphie encouraged her to follow her dreams and embrace the opportunity.

Physically, Charon possesses long mocha brown hair typically styled in two braids secured with star-shaped clips. She wears red rectangular glasses and favors casual attire: a black turtleneck sweater, a loose white overshirt, a brown-and-ochre skirt, thigh-high black socks, and brown boots. Upon transforming into her Lady form, her hair loosens into waves while remaining partially held back by the same star clips, making her the only main character with a significant hairstyle change in this state.

Her personality combines kindness, introversion, and low self-esteem. She is deeply passionate about literature, spending much time reading or writing, driven by her ambition to become both a picture book author and romantic novelist. Despite her timidity, she demonstrates strong loyalty to friends like Momona and Mizuki. She remains characteristically oblivious to romantic advances, particularly those from the persistently affectionate prince candidate Levin, whose attention often annoys or confuses her.

A significant story arc involves her anonymously writing a novel, initially kept as a draft. She accidentally sends it to all Petite Ladies, sparking widespread curiosity about its author. Levin discovers her secret early and assists her in continuing her writing covertly, including late-night library sessions. When nearly caught by security, Charon drops her notebook, later found and reported to Lady Rector. Levin falsely claims authorship to protect her, resulting in his house arrest. Feeling guilty, Charon confesses the truth and shares his punishment. This ordeal strengthens their bond, with Levin admiring her integrity and honesty.

Charon's relationship with Levin evolves through shared tasks and challenges. He consistently supports her, calming a crying child during a task, reassuring her in a haunted house, and comforting her homesickness. During a sunset conversation, Levin confesses his feelings, deepening their connection. In a pivotal moment, he proposes marriage with a fireworks display spelling "Marry me, Charon," which she accepts. Their engagement marks a key development, moving her from romantic obliviousness to mutual commitment.

Her journey concludes with ongoing closeness to Levin and continued dedication to her Petite Lady training, balancing her literary aspirations with her responsibilities as a Jewel Candidate.