The Records of Searching for the Supernatural say: Beyond the South Sea live merfolk. They dwell in the water like fish and never stop weaving. When they weep, their tears become pearls.
Xiang Tianxiao, who'd been poor for most of his life, fished a little brother out of the sea. He even had a tail.
He thought his fortune had finally come, and that he could sell pearls and reach the pinnacle of life.
But...
Xiang Tianxiao: Little brother, why are you a ball?
