Dr. Atsuko Chiba, born June 25, 1980, is a 26-year-old psychotherapist and lead researcher at the Institute for Psychiatric Research. Her surname Chiba (千葉) means "thousand leaves," and her given name Atsuko (敦子) signifies "honest child." Professionally, Dr. Chiba projects a serious, reserved, and clinically detached demeanor. Colleagues view her as cold, aloof, and intensely focused, exhibiting little patience for inefficiency or immaturity. She maintains a disciplined appearance, consistently wearing formal suits, pencil skirts, black pantyhose, and high heels, with her black hair secured in a bun. Chiba operates an unauthorized dream therapy alter ego named Paprika. This persona manifests distinctly with auburn hair in a bob cut, a tanned complexion, and casual Western attire including a red blouse, jeans, and sneakers. As Paprika, her personality shifts to playfulness, warmth, and approachability, contrasting sharply with her real-world self. This duality stems from Chiba's repressed desires and societal pressures for women to conform. Her key professional relationship involves collaborating with Dr. Kōsaku Tokita, inventor of the DC Mini dream therapy device. Though initially dismissive of Tokita's childish behavior and lack of self-discipline, Chiba gradually develops romantic feelings for him. This emotional evolution culminates in her accepting Tokita as her husband despite societal judgments about his appearance. Their union symbolizes her integration of the Chiba and Paprika identities, rendering the alter ego unnecessary. During the DC Mini theft crisis, Chiba confronts ethical violations and personal trauma. Her colleague Dr. Morio Osanai, harboring obsessive attraction and resentment of her authority, attacks her in both physical and dream realms; in the novel, this includes a rape attempt. These events force her to confront vulnerabilities beneath her professional facade. The climax features dream and reality merging catastrophically. Chiba's reconciliation with Tokita becomes pivotal to resolving the crisis, solidified by her public declaration of love. This admission facilitates their unification against the antagonist and ultimately restores reality. Her character arc concludes with adopting Tokita's surname and retiring the Paprika identity, signifying full self-acceptance.