The eight powers defined in the previous two posts will determine the number of dice that kami get to keep when intervening in the world in a supernatural way. What, then, determines the number they get to roll?
Here, I want to use the interests of the kami. As I said when introducing kami, every kami has her own interests, and is more likely to help in that area. In mechanical terms, this works well as a source for the number of dice to roll. A more powerful kami, with higher scores in the powers of her aramitama and nigimitama, is able to benefit you more in any area, but you might be better off going to a slightly weaker kami with more interest in that area. If two kami have the same power, then you definitely want to go to the one with more interest.
Unlike the powers, I don’t think that the possible interests of the kami can be fully captured by a list. There are just too many choices. However, there are a number of standard options.
First, all kami have an interest in the keidai, the grounds of their jinja. This allows them to act to defend or transform that area. It also allows them to act on anyone who is within the keidai, even if there is no other applicable interest. In this case, however, the effect only remains as long as the person is within the keidai, because that is how they have been linked to the power. This will be useful in stories, as it allows kami to act very flexibly when personae are on the kami’s home territory.
Second, almost all kami have an interest in their ujiko, and the area where their ujiko live. This interest can be used to do anything to the ujiko, or to the area. Ujiko who stop living in the area lose this connection, but simply working outside, or going on holiday, does not break it. (Consistently working in the area covered by a jinja may also qualify someone as an ujiko for game purposes; I’ll see how that goes.)
For most kami, the interest in their keidai should be their highest general interest, and for those kami who have ujiko, that should be the second highest, or at least no lower than any other general interest. This has the effect that it almost always makes sense for ujiko to go to their local kami, no matter what the subject of their request, which fits with actual Shinto practice.
A third kind of interest is a personal relationship with an individual. This is what a sūkeisha relies on. These personal relationships could potentially be higher than the interest in the ujiko or keidai. While sūkeisha are most likely to find it necessary to build such a relationship, there is nothing to stop an ujiko, or even shinshoku, from building a personal relationship that is stronger than the general bond to the ujiko.
When two or more interests apply to a use of a power, the kami uses the highest to determine how many dice to roll. Therefore, an ujiko with a strong personal relationship would use that relationship, rather than the general ujiko relationship, to determine how many dice the kami rolls to grant requests, or interfere in her life. There is a Japanese saying that “Kami you do not touch, do not curse you”. In the game, this rule is the reason. If you have nothing to do with a particular kami, she has neither reason nor ability to use her supernatural powers on you.
The other possible interests of a kami are very diverse. Types of natural phenomena, areas of human endeavour, healing, particular diseases, business prosperity, passing exams: these are all examples found among actual kami. For game purposes, there probably needs to be a fixed list of the most general interests, combined with guidelines for more restricted interests. While a narrow interest works the same way as a broad one, providing dice to roll, it should be easier to increase, so that it makes sense for players to define kami with narrow interests.
How many interests should a kami have? There should be no limit on personal relationships; every persona should be able to have a relationship with every kami in the game, although they probably won’t. For general interests, half a dozen is probably a reasonable maximum. More than that, and it will be hard to remember what the kami does. Naturally, this should not be a hard limit, but it is something to bear in mind when creating new kami.