A couple of weeks ago, one of the regular opinion columns in Jinja Shinpō was extremely thought-provoking.
Japan has fifty or so jinja enshrining soldiers and other people associated with the military who have died on active service since the mid-nineteenth century. Yasukuni Jinja in Tokyo is by far the most famous (and controversial), and I wrote a whole essay about it for my Patreon. However, almost every prefecture has its own jinja, called a Gokoku Jinja, “Country-Protecting Jinja”, enshrining the war dead from that prefecture. (Tokyo does not have one as far as I am aware, presumably because Yasukuni Jinja is there, and for historical reasons a few prefectures have more than one.)
These jinja all have a serious problem. It is almost 75 years since any member of the Japanese military (or even of the not-military-definitely-not-why-would-you-think-that Self Defense Forces) last died on active service. This means that the number of people who can remember any of the people enshrined there is very small, and shrinking rapidly. There are priests working at these jinja now who are likely to see the death of the last person who remembers anyone enshrined there, and will certainly do so unless Japan gets dragged into a war in the near future. Thus, the level of support for these jinja is also declining.
Obviously, this is a fantastic problem for a jinja for the war dead to have, but it is still a problem. From a religious perspective, simply ceasing to venerate the kami is not a viable option.
The column suggested a solution. The author remarked that he is occasionally asked about a suitable kami to pray to for success in sports, and he gets a bit stuck. Traditional Japanese martial arts are covered, and there are kami associated with victory in competitions, so that aspect can also be handled. And, of course, the Ujigami-sama can cover anything local. However, because sports in the modern sense were only introduced to Japan in the late nineteenth century, the traditional kami are not particularly associated with them.
On the other hand, a lot of the war dead were also sportsmen, because they were young Japanese men who had grown up in the late nineteenth and early twentieth centuries. (There are some women enshrined, because military nurses were also enshrined, and so I suspect that there are also sportswomen among them.) This means that Yasukuni Jinja and the Gokoku Jinja enshrine kami with a direct association with sport. They could therefore become the kami of sports.
There is a very famous precedent for this sort of transformation. Tenjin-sama, Sugawara no Michizanë, was originally revered as a kami of storms and retribution, but because he was a famous scholar while he was alive, people gradually shifted to regarding him as a kami of scholarship, and today that is almost exclusively how he is seen.
I suspect that Yasukuni Jinja is too tied to other associations for such a transformation to happen in the near future, but the regional Gokoku Jinja are much less known, and much less controversial, so maybe it could happen there. I do not know whether it would be possible, but it is the most positive suggestion I have yet heard for how the Gokoku Jinja could survive for another 150 years.