This thing is a work in progress, but I think I have a good idea here and I wanna know what you guys think.
So the basic synopsis is that it begins with Kovu and Kiara's wedding ceremony. As the ceremony is going on, we see that Vitani is inwardly jealous at Kiara's new family. We then see the opening title and the story fast-forwards to a few years later, where we see Kiara and Kovu's daughter Upendi and Vitani's son Chuki (the father ran off, leaving Vitani to raise him alone) are now very close friends. Back at the pride, Kovu and Kiara are being trained by Simba in the ways of ruling. Vitani is now the lead huntress of the pride, but still harbors resentment over the fact that she does not have a traditional family as Kovu and Kiara have. She is still jealous, mainly because she is approaching middle age and is becoming less and less desirable and she feels that time is running out. Meanwhile, Upendi and Chuki have grown accustomed to visting their great-grandmother Sarabi, who enthralls them every visit with stories of the old days. But after witnessing an argument between Kovu and Vitani the previous day, Sarabi decides to tell them a different kind of story, the story of Mufasa and Scar, which she says is going to take multiple visits to tell (My version of the story of Mufasa and Scar is going to deviate a little from the TLK:6NA version), end ends each of the three installments in the story throughout the rest of the film on a cliffhanger. Meanwhile, as the story is being told to Upendi and Chuki, Vitani and Kovu are almost replaying certain aspects of the story. As tensions between the two escalate and culminate with a physical altercation one day, Sarabi decides to intervene and recite out loud the conclusion of the story of Mufasa and Scar, which we all know ends in a tragically from watching the first film. Not wanting to meet the same fate, Vitani and Kovu reconcile. The film ends with Kovu and Kiara being coronated King and Queen of the Pride Lands some time later on as Vitani happily watches on with an older Chuki, content with her own version of a family.
It's basically just an idea at this point, so feel free to tell me what you guys think of it. XD