Dr. Kosaku Tokita is a research scientist specializing in psychiatric technology at the Institute for Psychiatric Research. He invented the groundbreaking DC Mini device, enabling therapists to enter and interact with patients' dreams for therapeutic purposes. This revolutionary creation in dream therapy research established him as a leading expert despite his young age. Morbidly obese, Tokita has short brown hair and brown eyes. He frequently wears an orange shirt and displays a consistently large appetite, often ordering multiple dishes during meals. His personality blends childlike enthusiasm, eccentricity, and intellectual brilliance. He exhibits innocence and naivete in social interactions, sometimes causing problems through unpredictable behavior. Despite this, he remains helpful, jovial, and friendly. He maintains calmness and focus during high-stakes situations, particularly crises involving his invention. Tokita shares a close professional relationship with Dr. Atsuko Chiba, whom he affectionately calls "At-chan," relying on her guidance. He harbors romantic feelings for her, believing she has been attracted to him for some time and interpreting her occasional sternness as unconscious repression of these feelings; his feelings were initially unreciprocated. When a DC Mini prototype is stolen, Tokita becomes instrumental in the investigation. He identifies his missing assistant, Kei Himuro, within the dream sequences of affected colleagues, confirming the theft originated internally. During the subsequent crisis where dreams and reality merge, Tokita is captured by the dream terrorist's influence. Within the collective dream space, he manifests as a giant robot-like entity that consumes Chiba. This crisis prompts Chiba to confront her repressed romantic feelings for Tokita, leading her to publicly acknowledge her love. Following the resolution of the dream invasion, Chiba adopts Tokita's surname, strongly implying their impending marriage. Professionally, Tokita demonstrates increased independence and problem-solving capability during the DC Mini crisis. His actions contribute directly to resolving the conflict, marking a development from his earlier reliance on Chiba. His enduring passion for creation and dream exploration remains central to his character, driving his scientific pursuits.