Nita kept the amulet all these years, and it turns out the thing has spiritually linked her to Kenai. Apparently, childhood friendship + amulet = unbreakable eternal bond, so unseen spirits begin working to destroy her current relationship with an actual human who never became a bear. At one point they attack her with a cock-blocking earthquake, and she has to consult with a shaman to learn more. So to recap, ghosts have mistaken an amulet for a lifetime sex contract, and are tearing the very Earth apart to make sure this engaged woman leaves her fiance to let a bear's bone-filled penis enter her tender human parts.
According to the self-professed "sha-wo-man" -- a joke taken from the world's lamest wizard's novelty mug -- Nita has to burn the amulet to break the enchantment. Although when an enchantment requires that you bang a bear, "curse" might be a better word. But this isn't the story of Nita weaseling her way out of necklace contracts. She quickly reunites with Kenai, and for a brief time it goes from Lord Of The Rings to Barnyard Taboo Sluts Volume 7. The two start to warm up to each other, which escalates to playful flirting, which escalates to Kenai neglecting Koda, undoing all the hard work of the first film.
The next act sees Nita breaking the amulet's curse and going back to her human-on-human relationship. At least, until she abandons her betrothed again to go back to Kenai. The two share some tender romance and declarations of love, until finally the girl's father shows up and magic lights start firing out of the sky. It's a strange scene that feels like it was written in response to the script note "HUMAN GIRL FUCKS BEAR!?" By the end of it, Nita has floated into space and been beamed back down as a bear. And what little girl doesn't dream of having her DNA rewritten in front of her father so she can mate with the primal beasts of the forest?