Dong An is earnest and kind, cares about others, and is a little lively yet slow on the uptake. She loves medicine and wants to save the world. Huaining Chen, by contrast, is cool and quiet, with a strong preference for her and an overwhelming possessiveness. Pure and pristine on the surface, with a touch of darkness underneath, he excels at both swordsmanship and medicine. One is determined to become a doctor who saves the world; the other wants to be the one who loves him devotedly.