At the start of the film, Kristoff is seen among ice harvesters as a young boy (he is 8 years old at this point, according to Disney). He is trying to learn their ways however he can as he tries to harvest ice himself, along with his reindeer calf, Sven. On one fateful day, Kristoff is following behind the other harvesters when he notices the King and Queen of Arendelle rush by him with their two daughters rapidly, the grass freezing as they travel by. Curious, Kristoff follows them to the Valley of the Living Rock and discovers the trolls. He and Sven watch from a distance as the elder troll, Pabbie, heals Anna but erases her memories of Elsa's ice powers. As they spy, they are discovered by one of the trolls, Bulda, and she decides to take in the two orphans. From there, Kristoff and Sven became family with the trolls, officially taking residence in their valley. 13 years later, Kristoff and Sven sell ice in Arendelle for business, and are seen out in the village during Princess Elsa's coronation after the death of the original monarchs. Whilst the kingdom is abuzz with royals from all around, Kristoff and Sven are out and about too, but don't attend the castle festivities, likely because it's meant for royalty and VIPs only.