Shen Kuan is the antagonist of the story, a son-in-law who married into the Tan merchant family. He pretended to be a devoted husband to Tan Tinglian but was actually scheming to seize the Tan family inheritance. He deliberately prepared medicinal soup containing appetite-stimulating herbs for his pregnant wife, causing her to eat excessively and resulting in an oversized fetus that nearly killed her during childbirth. He also poisoned Tan Merchant with infertility medicine to prevent the Tan family from having more heirs. He regretted going to the Hall of Hundred Herbs where he encountered Jiang Yao, as her involvement led to his scheme being exposed. His family formerly dealt in medicinal herbs, which gave him knowledge of herb properties. He had also been suspected of being involved in the death of Tan Merchant's son.
