For me, the Utsuro Bune is a very fascinating text. The objects and character make the story very mysterious. The shape of the boat was strange. It is very difficult to navigate over a long distances with this kind of boat. The circular shape is not optimal to move on water.
The boat was clearly built to protect the passengers. It is closed and the openings were covered with glass or crystal. It seems to me that the device had been built for a purpose other than that of navigation at sea.
The inscriptions on the boat are unknown. The symbols are strangely similar to those witnesses have observed on UFOs. What could be the utility of the box which the young woman did not want to abandon? According to me, the box was necessary for her survival. Or to return where she came from.
We will probably never know if the story of the young woman was real and if so, from where she came. Why was she alone at sea? If the woman of the Utsuro Bune sailed in this boat voluntarily or if she was put by strength, in both cases, it is an achievement to have survived to the shores of Japan.
The symbols resembling those seen on UFOs and the shape of the vessel suggest that it is possible she came from a extraterrestrial civilization.