The December 16th issue of Jinja Shinpō had an article about an overseas jinja and, coincidentally, it was founded from Okuni Jinja. The jinja is in J-Park Sriracha, and given that the katakana transcription of “Sriracha” was “Shiracha”, I am not going to transcribe any of the other Thai names from the article, because I would almost certainly get them horribly wrong.
J-Park was built to cater to local Japanese expatriates (I get the impression that Japanese car companies have a significance number of factories in the area), and to give them somewhere to mix with locals. Reading between the lines, it seems that an adherent of Okuni Jinja was one of the expatriates in the area, and that they suggested building a jinja, and then contacted Okuni Jinja about it. Okuni Jinja was happy to support the project.
The physical structure of the jinja was built by Shizuoka Mokkō, a company in Shizuoka that specialises in kamidana, although they also make sanctuaries for use outside. The president of the company commented that she hoped that people would see the jinja, and become interested in their craftsmanship, allowing them to open up overseas markets. This company seems to have a very good relationship with the Shinto community, and actually has a photograph of Okuni Jinja on their website. (They have an online shop, and also a store on Amazon Japan (affiliate link!), which does appear to ship overseas.)
The matsuri for opening the new jinja was attended by the president of the company running J-Park, the Japanese ambassador to Thailand, the governor of the local prefecture (to translate the Japanese terms as they are translated when they refer to Japan — the appropriate terms for Thailand are probably different), the head of the Thai-Japan Association, representatives of local Japanese companies, and adherents of the jinja. The matsuri was performed by three priests from Okuni Jinja, including the chief priest, and one miko. There were about seventy people in attendance, so it seems to have been quite an important event.
The kami of Okuni Jinja is Ōnamuchi Ōkami, also known as Ōkuninushi Ōkami, and he is also the kami enshrined in this jinja. This is a process that has a long tradition (although I think this is the first time it has happened in Thailand). The kami of one jinja is enshrined in another, while remaining at the original jinja. The “new” kami is sometimes called a “separated spirit” or “part spirit”, but the idea is that the whole kami is present at both jinja. You do need the permission of the originating jinja to do this, and some jinja no doubt have traditional procedures for consulting the kami. Some of the most famous examples, such as Iwashimizu Hachimangū, near Kyoto, were founded at the direct request of the kami. One of the reasons for the prevalence of Inari jinja is that Fushimi Inari Jinja has traditionally been willing to provide kami for enshrinement.
My understanding is that this very often is a physical process. The kami is called into an object at the originating jinja, and then that object is taken to the new jinja. That may well be what happened in this case, because there is an interesting choice of wording in the description of the matsuri. It is called an “Enshrinement Announcement Matsuri”, not an “Enshrinement Matsuri”, which suggests that the enshrinement itself had already happened. (It is not, however, conclusive evidence for that.)
In any case, this is one more example of a jinja outside Japan that is clearly a legitimate jinja within the mainstream Shinto tradition. (The chief priest of Okuni Jinja is the head of the Shinto Political League, and you do not get much more mainstream than that in the Shinto establishment.) I very much doubt that it has a resident priest (the article does not mention one, and if one existed I would expect it to), so the local adherents will, presumably, look after it, probably with assistance from the staff of J-Park. In that, it is no different from most jinja in Japan.