Ryouko Mikado is a supporting character in the anime and manga series To Love-Ru. She serves as the school nurse at Sainan High School, where the main characters attend. Despite her youthful appearance, she is an extremely skilled physician with vast knowledge of both human and alien biology. Ryouko is often seen assisting the protagonist, Rito Yuuki, and his friends, providing medical care and advice when needed. Her calm demeanor and professionalism provide a sense of stability amidst the chaotic events that occur throughout the series. Additionally, she is known for her intelligence and caring nature, which endears her to both students and staff.