In the Pride Lands of Africa, King Simba and Queen Nala’s newborn daughter, Kiara, is presented to the assembled animals by Rafiki, a mandrill who serves as shaman and advisor. Simba’s father Mufasa proudly watches over the ceremony from the Heavens above. Kiara becomes annoyed with her father’s overprotective parenting. Simba assigns Timon and Pumbaa, a meerkat and warthog, to follow her. After entering the forbidden “Outlands”, Kiara meets a young cub, Kovu, and they escape from crocodiles while befriending each other. When Kovu retaliates to Kiara’s playing, Simba confronts the young cub just as he is confronted by Zira, Kovu’s mother and the Outsiders’ leader. Zira reminds Simba of how he exiled her and the other Outsiders, and she reveals that Kovu was to be the successor of Simba’s uncle and enemy, Scar.
After returning to the Pride Lands, Nala and the rest of the pride head back to Pride Rock while Simba lectures Kiara about the danger posed by the Outsiders. He then tells her that they are a part of each other. In the Outlands, Zira reminds Kovu that Simba killed Scar (in actually, was the hyenas) and exiled everyone who respect him. Kovu explains that he does not think it is so bad to have Kiara as a friend, but Zira realizes that she can use Kovu’s friendship with Kiara to seek revenge on Simba.
Several years later, Kiara, now a young adult, begins her first solo hunt. Simba has Timon and Pumbaa follow her in secret, causing her to hunt away from the Pride Lands. As part of Zira’s plan, Kovu’s siblings Nuka and Vitani trap Kiara in a fire, allowing Kovu to rescue her. Simba is forced to accept Kovu’s place since he rescued Kiara. Later that night, Simba has a nightmare about attempting to save Mufasa from falling into the wildebeest stampede but is stopped by Scar who then morphs into Kovu and sends Simba to his death.
Kovu contemplates attacking Simba, but he is interrupted by Kiara and starts spending more time with her. Kovu becomes conflicted between his mission and his feelings for Kiara until Rafiki leads them to the jungle, where he introduces them to “upendi” (an erroneous form of upendo, which means “love” in Swahili), helping the two lions fall in love. That night, Simba allows Kovu to sleep inside Pride Rock with the rest of the pride after being encouraged by Nala to give Kovu a chance. Upon learning of Kovu’s failure to kill Simba, Zira sets a trap for them.
The next day, Kovu once again attempts to explain his mission to Kiara, but Simba takes him around the Pride Lands and tells him Scar’s story. The Outsiders then attack Simba, resulting in Nuka’s death and Simba’s escape. In the aftermath, Zira scratches Kovu for his brother’s death, causing him to turn on her. Kovu returns to Pride Rock to plead Simba for forgiveness but is exiled. Kiara makes Simba realize he is acting irrationally, and flees to find Kovu. The two lions later find each other and profess their love. Realizing that they must reunite the two prides, Kiara and Kovu return to the Pride Lands and convince them to stop fighting. Zira, however, attempts to kill Simba, but Kiara intervenes and Zira dies falling into the flooding river.
With his enemy gone, Simba accepts the Outsiders back into the Pride Lands, and appoints Kovu and Kiara as his successors.