As interesting as this is, it isn’t a UFO, nor even a UAP. As one can read in the Wikipedia article (or its translated sources), this appears to have more likely than not have been some new iteration of old folklore of strangers washing ashore in boats.

Speaking of boats, that’s what the image is of, depictions of the boat as it was described in the stories of the Utsuro-Bune incident. If you like odd folklore, I’d definitely recommend reading up on this or listening to a rundown of it.