On her first day in the palace, Yun Zhao, the daughter of a military family, throws Emperor Xiao Rui over her shoulder and sends him tumbling into a flowerbed. To her surprise, the emperor isn't angry at all. Instead, he excitedly insists on making her his big brother. From then on, the two climb trees, scale walls, steal vegetables, and drink wine, turning the solemn imperial harem into a chaotic world of adventure. Yun Zhao believes they will remain brothers for life, until the people around them grow old one by one, and the pear blossoms bloom and fall again and again. Only then does she realize that some feelings have long been hidden in their laughter and playful antics, accompanying them throughout their lives. But the words left unspoken will ultimately have to wait for their next lifetime.