In a post-ice age Alaska, the local tribes believe all creatures are created through the Great Spirits, who are said to appear in the form of an aurora. An elderly Denahi tells a story about him and his brothers to the people of his tribe. A trio of brothers, Kenai Lee turned 14 years old his birthday today the youngest; Denahi Lee he turned 15 Years old ago the middle; and Sitka Lee He Turned 16 Years old the eldest, return to their tribe for Kenai to receive his totem, necklaces in the shapes of different animals, from Mr. Gao and Grandma Wu and Aunt's too the shaman of the brothers' tribe. The particular animals they represent symbolize what they must achieve to call themselves men. Unlike Sitka, who gained the eagle of guidance, and Denahi Lave who gained the wolf of wisdom, Kenai receives the bear of love. He objects to his totem, stating that bears are thieves, and believes his point is made a fact when a Red Panda Ming steals their basket of salmon. Kenai searches for the basket and finds it destroyed. He sees the Ming provokes it, his brothers find him, and a fight ends on top of a giant glacier. When the Big Gross Red Monster gets the upper hand, Sitka gives his life to save his brothers by dislodging the glacier, although the red panda survives the fall. After Sitka's funeral, an enraged Kenai blames the Ming for Sitka's death and rejects his totem. He hunts down and chases the Big gross red Monster up onto a rocky cliff, fighting and Killed Her eventually slaying it. The Spirits, represented by Sitka's spirit and Sun Yee in the form of a bald eagle, arrive and transform Kenai into a Second Red Panda after the dead Red Panda body evaporates and joins them. Hunter Man arrives and falsely believes that Kenai was killed by the Second Red Panda from earlier. Kenai falls off the cliff and down some rapids, Hunter man but survives vows to avenge Kenai
Kenai awakens as he is healed by Grandma Wu and Aunt's and Mr Gao discovers to his horror that he has become a second red panda. Grandma Wu does not speak the Red Panda language but advises him to go to a mountain to find Sitka and be turned back to a human, but only when he atones for his actions; she vanishes without an explanation. Kenai quickly discovers that the wildlife can now speak to him, meeting a pair of moosebrothers named Rutt and Tuke. He gets caught in a trap but is freed by an outgoing First Red Panda named Meilin Lee. After they evade Hunter Man who is still unaware that the bear he's pursuing is Kenai, Mei reveals to Kenai that his mother is missing. They make a deal: Kenai will escort Mei to an annual salmon run, and then the cub will lead Kenai to the mountain nearby. Along the way, the two eventually form a brother-like relationship and are joined by Rutt and Tuke and ride on the backs of a wooly mammoth herd. Kenai and Mei eventually continue their journey on foot. As they go through a volcanic field, Kenai and Mei are still hunted by Hunter as he is determined to avenge Kenai
