Yuuko Amamiya  

, 雨宮優子

Yuuko is an enigmatic girl that Hiro encounters in a church during Christmas Eve. She has a tendency to materialize and disappear suddenly, communicating with characters including Hiro and Miyako. Despite her mysterious nature, it seems that everyone already knows her. As the central figure of the ef story, Yuuko plays a pivotal role throughout the series. In the second installment, her connection to Himura is further explored. Yuuko is a compassionate individual who values companionship and maintains a strong facade even when distressed or wounded.