城山, Mask De Holmes
Shiroyama the self proclaimed Mask De Holmes is a high school girl. Seemingly always wearing a mask while in costume or not. Others consider Shiroyama to be somewhat strange though some arent scared of asking for any assistance in their mysteries. Shiroyama is seemingly quite clever as she solves the mystery through unorthodox means. Besides that she is overall helpful and enjoys playing detective even if it may be a bit chuuni.