There are countless species of kami—in theory, every type of animal, plant, object, and location could be served by its own type of kami. These are collectively called “wards” by kami, who often think of them similar to how a human might think of a young child placed into his or her care. In practice, there are far more wards in creation than there are kami. As such, all kami seek to reproduce and thus expand their influence—the more kami, the more wards what benefit from their protection. Accordingly, kami influence is usually regional in nature—the kami simply aren't numerous enough yet to protect all of creation.

Further complicating attempts to catalog and categorize kami is the fact that there seems to be no rhyme or reason as to what sorts of wards get specific types of kami. The jinushigami, for example, are a race of kami that associate with all manner of regions, while the kodama concern themselves narrowly with the protection of specific trees. To the kami, these apparently arbitrary classifications make perfect sense, and their attempts to explain the reasoning to others generally result in confused listeners and frustrated kami. One thing that does remain constant, though, is the relationship between a kami's size and the import of its ward. A kami associated with a knife, frog, or single pebble in a stream would generally be quite small and unimposing, while a kami associated with a mountain, redwood tree, or elephant would be proportionally larger and more powerful. Of course, even here there seem to be exceptions, and frustrated scholars often wonder only half-jokingly whether the gods themselves vary these rules only to cause scholastic arguments and frustration.

Kami come into existence either as a spontaneously manifesting spirit or as the reincarnation of a particularly noble soul. Souls of creatures who died to protect an element of nature are particularly prone to returning to life as a kami. In this latter way, many kami arise from the souls of dedicated rangers or druids who perished while defending their homelands, or monks who spent a lifetime meditating on the serenity of nature. Once reincarnated, however, few kami remember any of their former lives, and their forms never resemble their former bodies. The rare kami who do recall their prior lives are the kami most likely to become more than mere guardians—these kami often take class levels and grow quite powerful.

Kami exist as ever-morphing spirits rather than souls trapped in concrete forms. Most exist to watch over a single tree, stone, or bend of a stream, and can have no more influence on the world than a single insect. A kami spends the majority of its existence merged with its ward—in this shape, it has no ability to interact with the world at all, but it can observe its surroundings with ease. There is no reliable way to determine whether an object, plant, animal, or location is protected by a kami, so those who travel or live in regions where kami are common generally assume that everything has a kami guardian. The kami do little to dissuade this, since the belief that kami are present is often just as potent a protection as having a kami in the first place.

All kami can assume physical form. Most somewhat resemble their ward, but again, in apparent eagerness to baffle and frustrate scholars, this is not always the case. When a kami assumes physical form, it always initially appears adjacent to its ward, manifesting suddenly as if teleporting. It is considered impolite by kami to pop into view, though—most prefer to manifest bodies while hiding, such as behind a tree, then step out of hiding to reveal themselves to those they wish to speak to.

Kami are generally a peaceable race, cohabitating with friendly fey and other magical beings that reside in natural environments. Dryads and treants alike find the company of kami to be quite favorable, as these noble spirits are willing to defend their lands to the death. Being more destructive, troublesome fey find themselves unwelcome in lands overseen by kami, who use the power of nature itself to obliterate intruders who make a nuisance of themselves. Kami's peaceful nature never vanishes more quickly than when they face oni, however, for no other creature is as hated by the kami as these. Kami view oni as defilers of the natural world and monsters whose goals and actions are in direct conflict with those of the nature spirits. When oni are spotted in areas guarded by kami, all kami alert each other to this intrusion, and band together to root out the dark presence. The fact that when a kami falls from grace it runs the risk of becoming an oni has much to do with this hatred—essentially, kami see oni as physical proof of their race's capacity for failure and shame.

While kami are rarely evil, they place the protection of their wards above all else. Often, this puts them at odds with other creatures, and as a result, many tend to view kami as troublemakers at best and outright monsters at worst. The kami have little care for how they are viewed by non-kami, of course—what matters to them is the safety of their wards.

The most powerful kami are known as kami lords. These mysterious and unique creatures are fantastically powerful, often on par with demigods or greater entities.