From hui3r:

Beautiful bones. Rare in this world.

Those with bone do not have skin. Those with skin do not have bone.

Most people’s eyes are shallow, seeing only the skin-deep appearance and not the ‘bones,’ the appearance of the inside.”

The “bones” and “skin” are metaphorical and taken from an ancient text in which these actually are referring to inner and outer beauty, respectively. Most people are shallow and only see outward beauty and fail to acknowledge inner beauty.

The female lead, Shi Yi has memories of her past life in which her heart belonged to Zhousheng Chen. That life ended in tragedy for them, and in this life, her only goal and desire is to find him again… and one day, she does. He does not look the same, but she knows that beneath the outer appearance, it is him. He, however, does not remember her.