In 232 BBY, Brightstar was sent on a mission by Jedi Master Yoda, his lightsaber was stolen by the pirate Taborr Val Dorn. Kai then replaced it with another lightsaber gifted by Yoda.
Kai's lightsaber first appeared in Young Jedi Adventures: Jedi Training, a children's book written by Caitlin Kennedy and published May 2, 2023. The lightsaber was first mentioned in a StarWars.com article, "Begin Your Younglings' Training with Star Wars: Young Jedi Adventures Books – First Look," and first pictured in another article, "Star Wars: Young Jedi Adventures Release Date and Cast Revealed." Both articles were posted on February 9, 2023.