OVA
Description
Ryôko Mikado is the school doctor at Sainan High School, secretly an extraterrestrial hiding distinctive pointy elf-like ears beneath her brownish-red hair. She possesses green eyes, stands 171 cm tall, weighs 59 kg, and has body measurements of 95-58-91. Mikado fled the black market alien organization Solgam, which sought to overthrow Emperor Gid, finding refuge on Earth. She works as a physician for both humans and aliens, operating a discreet private clinic from her home where extraterrestrials seek medical aid.

Mikado exhibits a kind, optimistic, and playful personality. She genuinely cares for students like Rito Yuuki and his friends, offering support during conflicts. She finds amusement in Rito's accidental perverted mishaps and occasional shyness, sometimes teasing him – for instance, instructing him to undress Yami for treatment or encouraging Lala to add an aphrodisiac to chocolate meant for Rito. She remains unbothered by accidental physical contact or nudity, interpreting Rito's clumsiness as a unique talent rather than a flaw.

Her advanced medical expertise covers alien technology and cross-species physiology. She utilizes equipment like a regeneration tank, notably treating Yami after power overuse. She also constructed an artificial human body for the ghost Oshizu Murasame, enabling Oshizu to live physically; Oshizu now resides with Mikado and assists at her clinic, with Mikado maintaining a patient, motherly attitude toward her clumsiness. Mikado investigated Rito's recurring accidental groping, diagnosing it as "Cataplectic Indecency Syndrome" – a manifestation of suppressed impulses – and advised him to embrace it as an advantageous trait.

Mikado shares a long-standing friendship with Tearju Lunatique, her former schoolmate. She later reconnected with Tearju to update her about Eve (Golden Darkness) and facilitated Tearju's move to Earth as a substitute teacher. Mikado also acts as a caretaker for Celine, displaying a nurturing, maternal demeanor during babysitting. Her composed and experienced nature in handling awkward or intimate situations often contrasts with less mature characters, underscoring her role as a stabilizing presence.