Kai's lightsaber, also referred to as Kai's first lightsaber, is a lightsaber that Kai Brightstar, a Jedi Initiate, used during the High Republic Era.
Brightstar, in the year 232 BBY, was tasked with a mission by Yoda, who is a Jedi Master; during this mission, his lightsaber was taken by Taborr Val Dorn, a pirate. Subsequently, Kai received a replacement lightsaber from Yoda.
The first appearance of Kai's lightsaber occurred in Young Jedi Adventures: Jedi Training, a children's book authored by Caitlin Kennedy and made available on May 2, 2023. The lightsaber was initially referenced in a StarWars.com news piece, "Begin Your Younglings' Training with Star Wars: Young Jedi Adventures Books – First Look," and visually depicted for the first time in another article, "Star Wars: Young Jedi Adventures Release Date and Cast Revealed," alongside an episode of This Week! in Star Wars. Both the articles and the episode of This Week! were published on February 9, 2023. It was later identified as "Brightstar's saber" in the article "Meet the Young Jedi: Stars Jamaal Avery Jr. and Juliet Donenfeld on Making Star Wars: Young Jedi Adventures," which was published on May 19, 2023.