Chestnut and sunshine

A small chestnut tree grows on the branch of an old chestnut tree, embraced by the sun' s rays. However, one day he falls from his branch into the forest, where, in addition to many animals and other trees, he recognizes himself and is forced to face a great challenge - in order to return to the sun, he needs to grow into a tall, strong tree. However, winter is inexorably approaching the forest and the sun is disappearing with each passing day. Will the little chestnut tree manage to grow up? What kind of friends will he find in the forest? And what will they learn from them?