Onogoroshima (Kojiki: 淤能碁呂島 Onogoro-shima; Nihon Shoki: 磤馭慮島 Onogoro-jima) is an important island in Shinto. Onogoro literally means "muddy sea has the ability to bind rocks and stones accumulated to form a bridge".
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. 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 thrice in the Kojiki, at ch.3:3, ch:7:25, and ch.111:32.
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.