Watch the full Shinto series here: https://www.youtube.com/playlist?list=PLHsXddZFR9AO-GbFRwqoBUQnFabXy6YBr

I find it absolutely hilarious that a shrine exists venerating George Washington and Abraham Lincoln as kami.

This Hawaiian Shinto reminds me of the  syncretism of Christianity and traditional African religions that happened here in Brazil and other places in the Americas.

The Hawaiian shrine reminds me of the Vietnamese Cao Dai religion which you should definitely do an episode on.  They have saints like Charlie Chaplin and Herman Melville.

I would say it's both. Traditionalists might not accept people in other parts of the world but that won't stop people from believing, practicing, and adapting religions.

Actually in my city Santos, Brazil, hade a Shinto Shrine that was demolished to build a park in their place that has a Shinto portal and some few rocks of the old temple, the japanese people that came her 100 years ago practiced their religion but over time they would convert do catolicism like majority of brazilians to better adapt to our culture but have some japanese that even in this day attend to shinto shrines in São Paulo to some festitivites

It's important to realize that culture, land, history and religion are all connected. American Christians trace their religion to the other side of the world, but they can never really experience and understand the life style of the early Christians, or even modern ones who live in different cultures. It's even more important to understand this in the context of Shinto, which doesn't emphasize faith and biblical canon the same way that Christianity does.

Regrettably, the Tsubaki Grand Shrine of America closed their doors at the end of June in 2023. Rev. and Mrs. Barrish moved to Florida where I'm to understand they set up a small independent shrine.

All religions start out as indigenous. Some of them spread beyond the founding group, and others don't.

Religions are very interesting when dissecting the culture behind them.

I think the answer might be "both". I can imagine that when building a shrine outside of Japan, practitioners can conceive of Kami local to their own area. In polytheism and animisim there's the idea of "our local spirits/gods" and then also foreign ones, which are recognized but live elsewhere (and not in your local shrine).
I think that allows for shrines outside Japan that utilize the same ritual practices but recognize a different mix of Kami.
Imo I think shinto may be flexible enough to have shrines overseas, since ritual practice seems to just as or more important than believing in Kami.

Now I want to build a Shinto Shrine...

Imo, being a form of polytheism (see Edit below for clarification) and incorporating ancestor and nature spirit worshipping, Shinto certainly can find something in common with Neopagan traditions and maybe even New Age spirituality. This would make it possible for non-Japanese to incorporate Shinto practices into their religious lifes and, in the end, adopt Shinto practices holistically.

That being said, if a foreigner adopts Shinto on account of its similarity with that foreigner's, say, Neopagan beliefs, there would be a reason to ask, whether what has been adopted is actually Shinto and not some sort of "non-specific eclectic paganism" with Japanese aesthetics.

EDIT: Thanks for all the replies, certainly gives something to think about. A little clarification: by "polytheism" I did not mean the term in its strict sense of "worshipping a multitude of deities/spirits equally", but rather "the belief in multiple deities/spirits that can be worshiped in any number of ways". That would include henotheism, monolatry, etc.

Gotta get here early for the future world religion

In Sri Lanka also you can find an indigenous faith going well along with Buddhism - but it does not have a name as such. The idea of Kami is very much the same. Different from village to village and sometimes historical figures, other times related to some natural feature in the area, or even from the Hindu pantheon later become popular.
Many people who believe and even practice don't notice the difference - only when one learns about Buddhism (and see how people actually practice and believe) they notice two distinct religions intertwined in practice.

It is that, Buddhism does not replace any pre-existing indigenous belief - able to coexist and intermingle.

It's so strange to learn that Granite Falls WA has a Shinto shrine. I grew up there for a while and it's a VERY small rural town just below the Cascade mountains. It's also very conservative. That seems like such a random place to put a Shinto shrine!

Shinto is definitely indigenous to Japan. Something can be transported elsewhere, but that doesn't stop it from being indigenous to where it originated from. You can see this with all manner of plants and animals that have an indigenous location yet can be transported or migrate elsewhere.

I live in germany and in my hometown there is a shinto shrine. Very beautiful place

08:50 It's quite interesting that a lot of Western converts to Shinto practice their faith with what seems to me as characteristically born-again-esque fervour like daily offerings of prayer which to my Tokyoite sensibilities is quite foreign to say the least, while a vanishingly small percentage of urban population in Japan own a personal Shinto-specific altar as opposed to a more syncretised, part Shinto part Buddhist part vaguely ancestor-veneration kinda altar, to which then again as far as I personally know very few people pray or light an incense in front of on a daily basis.

This video needs at least one qualifying statement that was left out. Fushimi Inari in Kyoto, which is the head shrine of many Shinto shrines in Japan dedicated to Inari, is not part of Jinja Honcho. In addition there are any number of independent shrines. So when the spokesperson at the head office of Jinja Honcho makes statements regarding the number of practitioners of Shinto, that does not mean they are in anyway connected to that organization.