Lin Shufen, a single mother, sells honest, high-quality soy milk made with genuine ingredients. When the price of quality soybeans rises, she increases the price of her soy milk from 6 to 8 yuan. Her competitor, Jin Dashan, maliciously stirs up trouble, turning the neighborhood against her and sending customers flocking to his cheap 5-yuan soy milk. Her daughter advises her to add water to cut costs, but Lin Shufen would rather throw away forty jin of soybeans than dilute her product with a single drop of fake water. She takes her daughter to Qingmu Town and starts over. By winning customers' trust with genuine ingredients, she earns a strong reputation and secures a major contract for 500 bottles a day after helping an elderly man suffering from hypoglycemia. Meanwhile, Jin Dashan profits by mixing moldy, old soybeans with artificial flavoring, eventually causing mass food poisoning. Lin Shufen gathers evidence and promptly reports him. Jin Dashan is ultimately shut down and sentenced.