Mountain expert Li Weiguo wakes up to find himself transported back to 1979, inhabiting the body of a young educated urbanite sent to the countryside in Woliu Valley at the foot of Changbai Mountain. Drawing on his knowledge of the mountains and practical life experience, he grows from an ordinary, hardworking young man into a trusted mountain guardian respected by the villagers. Gathering mountain treasures, protecting the forests, and helping his neighbors, he gradually improves their lives. Along the way, he also grows close to the gentle and kind-hearted Yang Sisi. Together, they build a family and cultivate a happy life through their everyday moments, turning their simple days into an increasingly prosperous and fulfilling life as they write their own story in the Changbai Mountains.