Onogoroshima (Kojiki: 淤能碁呂島 Onogoro-shima; Nihon Shoki: 磤馭慮島 Onogoro-jima) is an important island in Shinto. The name derives from 自 (ono, "self") + 凝る (koru, "to coalesce, to aggregate together") + 島 (shima, "island").^[1]

According to the Kojiki, Onogoroshima was created (kuniumi) when the divine couple Izanagi and Izanami churned the sea with the Amenonuhoko (heavenly spear) from their vantage point on the floating bridge of heaven.^[2] When they raised the spear from the ocean, drops fell from the spear, forming the island. They built a palace on top with a great column in the middle. The siblings walked around this pillar in opposite directions, and when they encountered each other, they were married. This island is where Hiruko (Ebisu) was born. The island is mentioned only three times in the Kojiki, at ch.3:3, ch:7:25, and ch.111:32.^[3]

In his Kojiki-den, a commentary on the Kojiki, the great Kokugaku scholar Motoori Norinaga asserted that it referred to one of the small islands near Awajishima (e.g. Nushima or Tomogashima). On the island of Nu/ Nushima (Japanese: 沼島), there is a shrine commemorating both Izanagi and Izanami, Onogoro-jinja (Japanese: 自凝神社) on top of a sacred hill revered by all Japanese is where the first island of Japan is created – i.e. Nushima, then followed by other creation of islands.

Nushima (沼島)

Nushima is a mysteriously shaped island like a magatama from the sky, located 4.6km above the southern sea of Awaji Island. In 1994, a very rare rock was discovered on this island, and it is called "Sayagata-shūkyoku (鞘型褶曲, i.e. "Sheath-shaped Fold)", which is regarded as the "Chikyū-no-Shiwa (地球のしわ, i.e. "Wrinkle of the Earth")". It is around 100 million years old.

There are many rocks and reefs on the shoreline of Numashima, and on the southeast coast, a towering giant rock “Kamitategami-Iwa (上立神岩)” with a height of about 30 metres which looks like a spear, has become a reminiscent symbol and icon that became the origin of the "Birth of the Japanese nation" (kamiumi). This rock, which appears as in mythology, is also called "Ame-no-mihashira (天の御柱, "the Pillar of Heaven") and is said to be the one Izanagi and Izanami descended to.

• Donald L. Philippi tr. Kojiki, Princeton University Press, Tokyo University Press, 1969
• Kurano, Kenji; Yūkichi Takeda (1958). Kojiki, Norito. Nihon Koten Bungaku Taikei (in Japanese). Tōkyō: Iwanami Shoten. ISBN 4-00-060001-X.

v t e Japanese mythology
Mythic texts	Kojiki Nihon Shoki Fudoki Kujiki Kogo Shūi Hotsuma Tsutae Nihon Ryōiki Konjaku Monogatarishū Shintōshū Butsuzōzui
Japanese creation myth	Kotoamatsukami (Hitorigami) Ame-no-Minakanushi Kamiyo (Kamiyonanayo) Kuniumi Kamiumi Izanami Izanagi
Takamagahara mythology	Amaterasu Susanoo Tsukuyomi Ame-no-Uzume
Izumo mythology	Yamata no Orochi Hare of Inaba Ōkuninushi Kuni-yuzuri Takeminakata
Hyūga mythology	Tenson kōrin Ninigi Konohanasakuya-hime Toyotama-hime
Human age	Emperor Jimmu Tagishimimi Kesshi Hachidai
Mythological locations	Ashihara no Nakatsukuni Amano-Iwato Onogoro Island Ne-no-kuni Ryūgū-jō Sanzu River Takamagahara Tokoyo no kuni Yomi
Mythological weapons	Amenonuhoko Kusanagi no Tsurugi Totsuka-no-Tsurugi Ame-no-ohabari Futsu-no-mitama [ja]
Major Buddhist figures	Amida Nyorai Daruma Five Tathagatas
Seven Lucky Gods	Benzaiten Bishamonten Daikokuten Ebisu Fukurokuju Hotei Jurōjin Kisshōten
Legendary creatures	Dragon Kappa Kitsune Oni Shinshi Tengu Yōkai Yūrei
Other	Shinigami Ryukyuan religion Amamikyu Tenson dynasty Ainu mythology Kamuy Kamuy-huci Hasinaw-uk-kamuy
Shinto deities Japanese deities Sacred objects Japanese religions Glossary of Shinto