The Eighties: A Delicate Beauty is a feel-good novel set in a bygone era. The older sister, a supporting female character, grew up in the countryside. Dark-skinned and coarse-looking, she is narrow-minded and jealous, a laughingstock whose sole purpose is to make her younger sister, the heroine, look better.
The little clam spirit Song Yingying was happily burrowing in the sand on the beach when a bolt of lightning struck her, turning her into the book's supporting female character.
...Dark-skinned and coarse-looking? Jealous? Here to make the heroine look good?
Sorry, this lady has spent a thousand years cultivating herself and has always been the prettiest little spirit in the sea!
Sweet, delicate flower (not really) heroine x cold, chaste (also not really) hero
Theme: No particular message, just a sweet romance.