Tanaka Kazuo. Distinguished Professor at Gifu University. Born in 1947. Specializes in optical information engineering, but has also lectured on skeptical thinking. Leading researcher of the utsurobune (hollow ship) legends.
In 1803, a round ship washed ashore on the Japanese coast, and a beautiful woman in strange clothes and a box in her hands got out of it. She could not communicate with the locals, and her craft was marked with mysterious writings.
This story of the utsurobune, or “hollow ship”, in Hitachi Province (now Ibaraki Prefecture) appears in many records from the Edo period (1603-1868), and Tanaka Kazuo, emeritus professor at Gifu University, has studied the subject for many years.
What made him move away from his main field of research, applied optics, and take up the study of this curious episode? And what really happened?
“Like a flying saucer”
Tanaka says he began studying the ship after the deadly 1995 subway sarin attacks by the Aum Shinrikyo cult. “There were many reports of the prophecies of the founder of Aum, Asahara Shoko, and his claims that he could float in the air.
At the same time, the older members of the cult were part of the scientific elite. I began to lecture, considering the paranormal from a scientific point of view, which meant that I collected all sorts of materials for teaching, such as about UFOs in the US and Japanese folklore.
While doing this, I stumbled upon the legend of the utsurobune.” He adds: “Long before the American UFO stories, the ship depicted in Japanese documents from the Edo period somehow looked like a flying saucer. It fascinated me.”
UFOs became a modern-day sensation after the media reported on June 24, 1947 that American businessman Kenneth Arnold had witnessed “flying saucers”. A flood of similar stories followed from around the world.
The most famous was the claim that in July 1947 a UFO fell to the ground near Roswell, New Mexico. “However, no debris or alien bodies were ultimately found,” Tanaka says. Only mixed eyewitness accounts remain.
“It was the same with all other UFO stories from around the world – they were mysteries without any significant evidence. The legend of the utsurobune, however, has a number of documents that can be considered as clues, so in this sense, for researchers it is a mystery with content.
There are similar oral traditions about “hollow ships” throughout Japan during the Edo period. Tanaka’s research focuses on various documents that describe the 1803 Hitachi Incident and include illustrations of a beautiful woman and a strange vessel, although they give different dates.
One of the best-known sources is Toen shōsetsu (Toen’s Stories), an 1825 collection of fantastic gossip written by the Toenkai literary circle and edited by Kyokutei Bakin, famous for his long historical novel Nansō Satomi hakkenden (Chronicles of Eight dogs”).
Others include Ume no Hiri (Plum Dust) by Nagahashi Matajiro from 1844, and collections such as Ōshuku zakki (Notes of Ōshuku).
To date, he has found 11 documents related to the Hitachi utsurobune legend, of which the most interesting date from 1803, the same year the ship is said to have washed ashore.
One of them is “Mito bunsho” (Mito Document) owned by a collector from Mito, Ibaraki Prefecture. Tanaka noticed that the dress of the woman in the illustration in this work is similar to that of the bodhisattva statue at Shofukuji Temple in Kamisu, also in Ibaraki, which is dedicated to silkworm breeding.
Legend attributes the beginning of sericulture in the area to Princess Konjiki (or “golden princess”), which is the motif of the images in the temple. According to one version, Princess Konjiki was washed ashore after traveling from India on a dug out boat in the shape of a cocoon.
She repays her kindness to a local couple who try to restore her health by passing on the secrets of sericulture to them when she herself becomes a silkworm after death. Among the various materials, only the illustration in Mito’s document seemed very similar to Princess Konjiki.
Another even more important source is the “Banke bunsho” (Banke Document) owned by Kawakami Jin’ichi, heir to the Koka ninjutsu (art of ninja) tradition, ninjutsu researcher and martial artist. It is named after the Banke family, or Ban, Koka ninja.
While some other material states that the ship made landfall at places like Harayadori or Haratonohama, there is no evidence for such places.
In this document, however, the site is recorded as Hitachihara Sharihama, which appeared on a map drawn by renowned cartographer Ino Tadataka and is now known as Hasaki Sharihama in Kamisu.
Tanaka comments that while other materials show geographical inconsistencies, this document mentions the real name of the area.
He says that Kawakami suggested that one of Banke’s members may have been collecting information while working for the head of the Owari Domain (now Aichi Prefecture). “If that’s the case, then he wouldn’t write down lies, so we can say that the document is very reliable.”
Folklorist Yanagita Kunio once said that all the legends about utsurobune are baseless fabrications. “But in the case of the utsurobune from Hitachi, there is a distinct difference from other stories around the country,” says Tanaka. “First of all, it is stated that this happened in 1803.
And then, it is strange that there are specific photographs of the ship in which it looks like a flying saucer. I think that most likely it was based on something that did happen.
But Japan was then pretty much a closed country, so if a foreign ship wrecked or foreign people arrived in the country, it would be a huge event and a government official would investigate and leave a public document.
When in 1824 British sailors entered the island of Ōtsuhama [now Kitaibaraki], this was one of the reasons for the enactment in the following year of the edict on the exclusion of foreign ships. So perhaps there are eyewitness accounts that something happened in Kasimanad for a short time. It is possible that this became connected with earlier legends about the utsurobune.”
Just as descriptions of a woman’s clothing vary from document to document, so do descriptions of the shape and size of her vessel. For example, the Castle Record says that it was about 3.3 meters high and 5.4 meters wide (in modern terms) and that it was made of rosewood and iron with glass and crystal windows.
“I’m not sure if the Notes of the Castanets were an official document. There are two volumes in total, and apart from the utsurobune, they all represent incidents that actually took place. This suggests that the author at least believed that the utsurobune really washed ashore,” says Tanaka.
There are countless mysteries associated with the “hollow ship”, for example, the meaning of the font written inside it.
Tanaka says that, according to one version, it resembles pseudo-Roman letters, which are sometimes found on the borders of ukiyo-e prints. “So it could just be decorative. Although it’s possible we’ll find evidence that it’s alien writing!”
Having said this, he laughs. “There are likely to be more discoveries of unknown utsurobune related materials and new revelations.
This legend is so attractive because there are so many different theories that can be made up. Having a similar story in Japan – 140 years before American UFO sightings – which is so stimulating imagination, reminds me of how deep and fascinating Japanese culture can be.”
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