Tang Dynasty Pygmalion with a twist: a nobleman trains a tea girl for a peace marriage (和亲) after his sister ran away, but falls for her. He's grumpy, honorable and rigid; she's spirited and sweet. Their relationship evolves from wariness to trust and then to love, and their romance is a slow burn with so. Much. Pining.  The emotions, yearning and the love are felt in the subtley of their interactions - every furtive look, every light touch (the lesson scenes!). 

The conflict of honor/duty vs. love is woven wonderfully, though I was just screaming for them to get together, lol. I also loved how they grow to become stronger because of each other. And the sensuality of their love scenes is perfect. Lin did a great job with the historical setting as usual but I wished their HEA was more drawn out (like another 50 pages more). P.S. Li Bai Shen is a treasure.