Ryōko Satō is a high school student who has completely withdrawn from regular school attendance due to severe bullying. She lives entirely within a self-created fantasy world, identifying as a researcher from another universe tasked with finding a magical artifact called the "Dragon Terminal." Her behavior manifests through constant cosplay, including wearing a distinctive blue cape and carrying a staff containing her personal belongings, which she uses to "detect magical vibrations."

Her condition stems from an inability to cope with reality, leading her to adopt an alter ego as a protective mechanism. This behavior isolates her socially and makes her vulnerable to escalating bullying, including verbal harassment, theft of her belongings, physical confinement in school closets, and violent threats. The persecution reinforces her retreat into fantasy as her primary means of emotional survival.

Her background reveals an estranged relationship with her physically absent parents. This lack of familial support contributes to her reliance on delusion. Her initial interactions with Ichirō Satō are marked by resistance, as he rejects her due to his own shame over a similar past. After witnessing her being bullied, he intervenes and gradually becomes her sole ally.

A critical development occurs when a classmate discovers Ichirō's past chuunibyou experiences and threatens exposure unless he abandons Ryōko. His temporary compliance devastates her, causing her to reject reality entirely and retreat permanently into her fantasy world. This culminates in a climactic confrontation where Ichirō, embracing his past identity, reaches out to her. His acceptance enables Ryōko to choose reality over delusion.

Her character development concludes with tentative progress toward normalcy, including returning to school and beginning to confront daily challenges alongside Ichirō. This resolution underscores her transition from isolation to connection.