You Zijin and Lü Ziye are sisters with very different personalities. One inherited their father's quiet nature, while the other took after their mother's lively, cheerful disposition. Zijin has no memories from before she was seven; their father's favoritism toward her younger sister cast a shadow over Ziye.
Ten years later, Zijin meets Yin Junze, while Ziye falls in love with Feng Yanbin.
Yet their similar personalities lead to misunderstandings and entanglements among them. After many twists and turns, they finally remember the past and find warmth again.
In the end, each kindhearted girl holds a clear, sparkling crystal apple, a symbol of the transparent warmth and happiness they have found...
It's too simplistic. Since it's a romance novel, it's too simplistic and there's no mystery.