Izanami is the most Earth-like component of a binary planet. The secondary component, Izanagi, is approximately two-thirds the mass of the the primary, and their orbital separation is only 280 000km. Izanami is highly tectonically active, but does not have distinct continental and oceanic plates. The world's most characteristic terrains are vast tidal flood-plains, swamps and marshes on the shores of the shallow oceans. Further inland much of the planet is covered by grasslands and tundra, crossed by impressive mountain ranges. Earthquakes and volcanic eruptions are frequent.

Although Izanami's gravity is stronger than Earth, the close orbit of Izanagi has stripped away much of its primordial atmosphere, leaving a surface pressure less than that of Earth. However, the nutrient-rich littoral regions host a prolific array of plant-life, resulting in a relatively high partial pressure of oxygen. The high gravity and low atmospheric pressure have led to a lack of large flying animals, but there are large populations of flying insectoids.


Izanagi has a high-pressure reducing atmosphere and several large bodies of water; it is similar in many ways to Venus early in its history. The Izanami colonists have mounted several expeditions to Izanagi, but have barely begun the task of fully surveying the world. It is still not known whether there is primitive life in Izanagi's seas.