Following her master and growing up in the mountains, Niannian steps into the East Palace due to a chance encounter, becoming the adopted daughter of Crown Prince Xiao Heng. Quick-witted and sweet-tongued, she loves sweet-scented osmanthus cake best and always manages to spot minor details others overlook. The stern crown prince learns to take care of a child, the serious elders gradually regain their smiles, and the East Palace is filled with joy and laughter from then on. Accompanied attentively by her family, Niannian studies diligently, learns the rules, and uses her kindness and wisdom to help those around her. As the past gradually becomes clear, she reunites with her family, making this warm big family even more complete.