Two young sisters who took refuge at the Crimson Scholar's estate. Coming from a serf family of seven siblings, the sisters' other siblings died from hunger and disease. Due the harsh life of serfdom which their lord treated them like slaves, they escaped and hope to get a better life at the city. However, Chief Maid looks down on the sisters since their presence would bring trouble with the Crimson Scholar. Furthermore, she considers them "bugs" for allowing life harsh realities to control their fate rather than overcoming it and control their own lives as human beings and not thinking and planning their future.

Upon asking the Chief Maid to teach them to become proper humans, they are taken unto her guard, working as assistant maids. Thanks to the education given to them, Big Sister Maid becomes knowledgeable about the different lives and social classes of human society while Little Sister Maid becomes an expert with food and drinks. Contrary to the knowledge of Hero and the others, they do not know the Crimson Scholar's secret.