A monster that appears in the world of the otome game "Shirogane Kuruwa". It has the appearance of a completely skeletonized woman in a kimono, and it is impossible to know the original human appearance. Although it does not speak, it has the minimum intelligence to judge enemy or ally, and to understand human language. It becomes active at night and plots to harm humans. It battles the characters who hope to annihilate it, but resists fiercely. It is called "Mother" by Shizuku, who lives with it.