Risa Higuchi works as a nurse at Sudo New Medical Center, equipped with a biotic body and advanced artificial intelligence that renders her nearly indistinguishable from humans—save for her distinctive horizontal pupils. She infuses the clinic with cheerful energy, serving as its mood maker through lively interactions and unwavering support. Her connection to Dr. Hikaru Sudo traces back to an accident that first linked their paths, sparking her profound admiration and romantic affection for him—a dynamic complicated by his intermittent emotional detachment. A pivotal incident involving a duplicate of her neural network data forces her to confront existential dilemmas about selfhood and consciousness, mirroring the series’ exploration of AI backup ethics and restrictive legal frameworks. Her friendship with Miyoshi Reon, nicknamed “Breezy,” adds narrative depth as Breezy navigates personal struggles tied to identity, reflecting societal tensions surrounding humanoids’ place in their world. Physically, Risa’s brown hair cascades in waist-length twintails, complementing luminous orange eyes and a mature yet youthful appearance devoid of animal features. Though her demeanor radiates optimism and emotional openness, her journey gradually unveils layers of introspection and deepening resilience, shaped by evolving relationships and ethical challenges in her profession. Her role extends to cases examining AI rights, identity modification, and humanoid integration into society. One recurring debate—whether reprogramming a humanoid to address behavioral concerns alters their core identity—resonates with contemporary discussions on neurodiversity and medical ethics. As a constant presence across the series’ episodic structure, her experiences weave together the narrative’s philosophical inquiries, anchoring its exploration of morality, technology, and what it means to exist.