They are the eldest daughters of Naiya, The kitsune are spirits of play, passion and deceit. Naiya could not control them and created the land of Sifan for their home. They have been described as fox-goddesses and in appearance are pretty young women with fox ears atop their head.
The Kitsune are extremely powerful, being described as arch-fairies. They are immortal. They are very sensitive to how they are addressed, requiring politeness and deference. They have a deep love of pranks. In fact, they are attracted to people playing tricks and almost compelled to join in the fun (8-22).
Created during the reign of the Infinite Order, the Kitsune ran wild. They were the beloved daughters of Naiya and she would protect them when they ran afoul other members of the Infinite Order. Nonetheless the Kitsune's cleverness and mischieviousness caused them to continually interfere in the affairs of the Infinite Order. Among other talents, the Kitsune were always able to infiltrate IO facilities, even locked ones. After some unknown inciting event, Rauzon the Prime (head of the Infinite Order) ordered their removal from the main continent. It is believed that Rauzon intended to execute them, but was talked down to simple banishment to the faraway land of Sifan, a continent which Naiya created just for the Kitsune.
The Kitsune remain the rulers of Sifan, exactly as they were situated millenia ago. The Kitsune supervision of Sifan has widespread effect. Sifan now embraced a bastardized form of Naiya's home oriental culture from Earth, as taught to the Kitsune by their mother. Sifanese, as a language supervised by immortals, is also largely static unlike other languages on the planet which cyclically evolve.
The Kitsune, following banishment by Rauzon with some consensus by the other Order members, were required to not be on the Tiraan continent, to stay out of IO member projects, and to accept their banishment. Several of the more daring Kitsune enjoyed making a game out of breaking the quarantine of the Kitsune Exclusion Zone. Several of the Valkyries would return the favor and slip away to Sifan to visit their older sisters. Kitsune such as Akane would sneak back to visit their mother Naiya, and consequently came into contact with Naiya's second generation of daughters, the Valkryies.