MILKY BEVERAGE, METHOD FOR PRODUCING MILKY BEVERAGE, AND METHOD FOR IMPROVING FLAVOR OF MILKY BEVERAGE [Problem] To provide a flavorful milky beverage. [Solution] A proline-containing milky beverage. This milky beverage may have the flavor of fermented milk. This milky beverage contains less than 3.0% of non-fat milk solids, and may contain less than 1,000,000 lactic acid bacteria or yeast cells per 1 mL. This milky beverage may be a yogurt flavored soft drink. This milky beverage need not contain amino acids other than proline. This milky beverage can be stored at ordinary temperatures. [No drawing to be published]