Mio is a girl who, on most days, would prefer to be left alone not because she's antisocial or anything but for a different personal reason. However, since a new academic school year is about to begin, it's unlikely she'll be able to remain alone for long but at least she has her childhood friend Reku to protect her from needing to interact with others.(Recommended that you read Azure Chronicles and Crusade of The Spirits for context since this story is a direct sequel, maybe also read Ruins of Archania)