this has some info about the Bakekujira

1. Bakekujira
When people think of a Great White Whale, they
normally think of Moby Dick, but this whale's white is the color of
its bones. The Bakekujira, a gigantic, skeletal baleen whale that
emerged and vanished off the coast of Japan under
unexplained circumstances, is only known by its bones. Is it some kind of monster? Is it a
phantom? Is it a deity? No one knows for certain.
What The Name Bakekujira means
With a subtle change in connotation, Bakekujira's name is similar to that of numerous
supernatural animals in Japanese legend. The kanji (bake; change) refers to a transformation,
the capacity to shift from one form to another, for most bake- beings (bakeneko, bakenezumi,
etc.). Bake does not relate to a metamorphosis in Bakekujira—(bake; change) + (kujira; whale).
It just sounds terrifying and strange. This is one of them.
The Tale of the
Bakekujira
Something huge and white
emerged off the shore of Shimane
prefecture's Okino Island one rainy night. Village fishermen watched it come closer and closer
till they decided to go out in a rowboat to see what it was. They guessed it was a whale based
on its size, but no one had ever seen one quite like it. They observed the waters of the ocean
glimmer as they rowed out of their boat.

2. One of the fishermen launched his harpoon as they approached the white whale, and it
went through the mass of white undetected. The fishermen eventually got a good look at the
monster, which was the skeleton of a giant baleen whale with no skin or meat on it, their vision
hampered by the pounding rain. But it was alive and moving.
The guys were scared, made much more so by the presence of unusual fish in the seas
and weird birds in the air. They noticed an island in the distance that hadn't been there before,
as if they'd rowed into some unknown nation. The vision abruptly ended, and the huge
bakekujira—as they dubbed it—retreated as fast as it had arrived back to the open sea.
When the fishermen returned to shore, they thought that it was the spirit of a whale slain
in a hunt or the presence of a foreign deity. The bakekujira, whatever it was, was never seen
again.
The History of the Bakekujira
That is all there is to it. There's only one narrative of the bakekujira's one appearance,
and that's all there is to know about the boney beastie. Everything else you've read about the
bakekujira has been made up to fill in the gaps.
In truth, despite its modern popularity, the bakekujira is
a limited and obscure yokai. There are no ukiyo-e
prints or Kaidan collections involving the bakekujira
among Toriyama Sekien's multiple Edo-period yokai
collections, at least not that I could find when
researching for this piece. In reality, the bakekujira was
initially mentioned by Mizuki Shigeru, whose cool
character design is mainly (if not entirely?) responsible
for the bakekujira's current popularity.
However, Japan has a lengthy tradition of whale gods and sacred bones, which the
bakekujira fits into. Allow me to go on to another facet of Japanese folklore: the Japanese
Whale Cults.

3. Hyochakushin – The Drifting Ashore God
Fishermen in pre-seafaring Japan were restricted to the coastal seas that their tiny ships
could reach before Samurai William introduced the secret of keels and ocean-going boats. They
scraped by on anything they could get their hands on. But now and again, the waves would
shower us with a bountiful harvest.
Whales would occasionally travel inland or beach themselves on the beach. Fishermen
used harpoons to kill the whales that were caught in the shallows, a method known as passive
whaling. This was a once-in-a-lifetime opportunity—a single whale furnished the town with huge
amounts of flesh and resources, and it felt like a gift from the gods. And the whale was only a
small part of the prize. Whales typically followed enormous schools of fish in, signaling a
profusion of sea life in addition to the leviathan itself. A whale's arrival might save a town on the
verge of famine and extinction. It was the seas' mana. Ion.
The people, like current Cargo Cults, had no idea where or why the whale had come into
land. The only thing they knew about whales was that they signified wealth and rare full
stomachs. Whales were thought to be embodied deities (; shintai), and whale cults such as
Hyochakushin (; Drifting Ashore God) and Yorikami Shinkyo (; The Religion of the Visiting Kami)
arose in coastal settlements.
The Whale and Ebisu
These early whale cults were rudimentary. The majority of those praying had only one
request: send more whales. They did, however, develop through time. The Whale Cults of
Japan, like many faiths, was founded on a mixture of reverence, gratitude, and terror. Because
whaling, even passive whaling, was a risky business, some whale cults viewed whales as
malevolent gods and prayed to please their spirits and calm their rage. Bad storms and low
catches might result in an enraged whale deity, which no one desired.
These whale religions eventually fused with another, more popular deity, Ebisu, the god
of abundance. Whales were regarded to be Ebisu's messengers at first, and subsequently as a
manifestation of Ebisu himself. Because whales were considered to have the ability to

4. manipulate fish, fishermen began carrying pictures of the deity Ebisu dressed as a whale to
provide them the same ability.
Whalebone Tori Gates
Japan had become a maritime nation and developed a whaling business and culture by
the Edo era. Official Whale Shrines were created and maintained by whaling associations in
coastal locations, and many of them still exist today. When Taiwan was under Japanese
influence, whale shrines were erected, generally devoted to Ebisu.
Whalebone Tori gates, with their gorgeous post-and-lintel pattern that denotes the
presence of a kami spirit, are the most striking of them. The Arch of Ebisu is the oldest
Whalebone Tori in Wakayama prefecture, Taijicho town. In his work Nippon Eitaigura (; Japan's
Warehouse of Eternity; 1688), Ihara Saikaku describes this Tori. However, the tori is most likely
considerably older. The Kaido Jinja in Nagasaki, Shinkamigostocho town, has the newest
whalebone tori (Shrine of the Sea). It was built by the Japan Whaling Association and dedicated
in 1973.

5. Sources:https://hyakumonogatari.com/2013/05/10/bakekujira-and-japans-whale-cults/