A world locked in a bloody war with its sister planet Lutani VII, whose conflict is the background to the Strange New Worlds documentary-style episode What Is Starfleet?
Kasar and Lutani VII are sister planets at war. As the third-season episode What Is Starfleet? explains, Kasar opened the fighting with an attack on its neighbour and seeks control of the Lutani system and its resources. The toll is very uneven: about nine million dead on Lutani VII against roughly 119,000 on the Kasar side.
The Enterprise is ordered to carry classified cargo to the Lutani, and it turns out to be a Jikaru, an immense moth-like creature that lives in space. The Lutani have altered it to use as a weapon against Kasar, seeing it as their one chance of winning.
Uhura argues for trying to communicate with the Jikaru, which proves to be intelligent. In the end the creature flies into a sun, asking Pike to protect its young. The story is told in the form of a documentary being made by Beto Ortegas.