As you can see from the photo, the Spirit Houses of South-East Asia do resemble hokora. They resemble tiny houses with pointed roofs, are not placed directly on the ground, and are often placed near sacred natural objects (such as a sacred tree). Offerings to the spirits are also placed by the Spirit Houses.
I find this overlap between Shinto and South East Asian folk religion extremely interesting. We often tend to think of Shinto as being the “native” Japanese religion, with the other main religion of Japan, Buddhism, being of continental Asian origin. But does the similarity of the kami to the South East Asian nature spirits, and the parallel in how they are venerated through hokora and spirit houses, hint at a historical link between the folk religions of Japan and South East Asia?
Or is the link a little broader than that? Not quite mere coincidence, it could be that the belief in folk spirits, and the need to venerate them in tiny house-like shrines, is fairly universal. The way in which the Romans venerated the Lares at a Lararium, and the current popularity of building tiny “faerie houses” in modern Western countries, would tend to support this idea.
Either way, I still find myself very much drawn to these tiny Spirit Houses from all cultures, and really want to make my own at some point.