OVAs bundled with the 15-17th volumes of the Mushibugyou manga.

This is a story about two sisters: Shizuru, is a high school student who is able to see ghosts while her younger sister, Mizuki, is haunted by these apparitions. Frustrated by their abilities, their parents decided to entrust the sisters into the care of their grandparents who live in the countryside. As they adapt to life in the countryside, Shizuru and Mizuki begin to learn about the importance of coexisting nature with these apparitions. (Source: ANN)

The story revolves around William, an aristocratic family's progeny with rare intellect. One day, his uncle lost his possessions after his business failed. Fearing that his family's name has been tarnished, William returns home and searches with his family's butler for anything that can be converted into cash. A search of the premises yields an underground room left by an ancestor. In the room is a magical seal, and William unintentionally summons a devil. The summoned devil tells William his name Dantalion, and reveals that William is the designator who can choose the acting ruler of the demon world. (Source: ANN)

In the country of Gazth-Sonika, civil war rages. There, a mercenary called Madlax plies her trade, with almost supernatural skill. In the seemingly peaceful country of Nafrece, Margaret Burton lives a tranquil life. As separate as their lives may seem, the two are connected by ties of mystery, and by a holy book that is also sought by the shadowy organisation, Enfant. As Margaret and Madlax follow the path of their destiny, they come ever closer to uncovering the truth - with no guarantee that it is a truth they can bear to learn. (Source: ANN)