Shortly after his birth, Kovu was named the chosen heir of Scar. However, once Simba rose to the throne, he exiled Kovu and his pride to the Outlands, where Kovu's mother, Zira, raised him to resent the Pride Landers and, in particular, the royal family. Kovu's view of the enemy pride was slightly altered when he encountered the princess of Pride Rock, Kiara, who had wandered into the Outlands in search of adventure. The two cubs formed a tentative friendship, though they were quickly separated by their feuding parents.

Upon finding out about Kovu's friendship with Kiara, Zira resolved to use her son to infiltrate Simba's pride and seize the throne. For years after, Zira trained Kovu to be a ruthless killer, and when it came time for Kiara's first hunt, she had her children set fire to the grasslands while Kovu was sent ahead to rescue Kiara. Kovu delivered Kiara safely to the Pride Lands, where he requested to join the pride. Simba reluctantly agreed, though he reserved judgment on Kovu's character.

Over the next few days, Kovu's attempts on Simba's life were thwarted by Kiara, whom Kovu began to grow fond of. The two's friendship slowly blossomed into love until Kovu resolved to tell Kiara the truth about his mission. Zira caught wind of Kovu's betrayal and framed him for an ambush, which led to his expulsion from the Pride Lands. Kiara sought Kovu out and convinced him to unite their feuding prides. Though Zira refused to see reason and died trying to kill Simba, Simba accepted the Outsiders, and Kovu was allowed to rejoin the pride. In a ceremony at Pride Rock, Kovu was accepted as Kiara's mate and the future king consort of the Pride Lands. Not long after, Kovu attended the coronation and wedding of his brother-in-law, Kion, to Rani at the Tree of Life.