Luka Urushibara (漆原るか, Urushibara Ruka?) is a close friend and classmate of Mayuri Shiina and so-called protégé of Rintaro Okabe. While feminine in appearance and personality, Luka is a male on most world lines. Mayuri often attempts to coerce him into cosplaying. He works at the Yanabayashi Shrine as a shrine maiden.