/jp/ - Otaku Culture

Rosa gave Maria the letter
Rosa knows that Maria refers to her other personas as different people such as the "Black Witch" and the "Golden Witch Beatrice" so that she can use Maria as a witness
Rosa is a fashion designer so creating an extravagant dress and wig and hiding it in her luggage would be an easy task
Rosa is the only human to ever refer to the servants as furniture and this was even with the "detective" present
Rosa had enough knowledge to solve the epitaph and did so before the conference on Rokkenjima