Kiara, Simba's headstrong daughter, meets an outlander named Kovu. Simba does not approve of Kovu because he knows Kovu was trained to follow in Scar's path. Now, Kovu's mom, Zira wants to take over Pride Rock.
[I originally posted this at The Lion King Source as ElChivato.]
I mean for a crime other than Scar's. Fanfiction is fun fun fun! But the bottom line is; in movie making if anything gets complicated, it would be somewhat or extremely directly explained - NOT hidden behind hints.
Even the director of TLK2 says "the seeds of it are in the first film". (In the Making of documentary "Proud of Simba's Pride".) And the last time I checked, no crimes happen in that film apart from the one committed by Scar. And because the second film did not specify any crime other than the one Scar committed, that's...