Kitsune are fox spirits that originated in Japan. They primarily work with illusion magic and have an ability called "fox fire" which looks almost like a will-o-wisp. Their energy and magic is very distinct. They are an often flirtatious race of spirits, and their colors depend on their amount of tails. In the group of Kitsune that I work with, the most powerful kitsune are white kitsune, who have survived for long lengths of time. They go from black to white throughout their time as a spirit, gaining tails as they gain magic abilities.
They are well known for pranking and general mischief-making throughout Japan, and can hurt people when not really meaning to. As spirits, though, they're a lot of fun and tend to lean on the protective side. They cause mischief and punish those that would otherwise attempt to harm their keeper. They are very energetic beings with vibrations that are easier to pick up on for beginning keepers.
Perhaps the largest benefit to having a Kitsune around is their ability to aid in ritual work and spellweaving. They are almost intuitive with the flow of energies, and can certainly enhance the work you're already doing. They are often looking to share their knowledge, no matter how goofy they act, and can certainly be helpful when they're not more interested in a prank or a plan.