In a world where the visualization of biometric information through wearable devices such as smartwatches is becoming an everyday occurrence, "visualizing emotions" and "their utilization" are keywords for "diversification of needs" in various markets. It is expected to become an important technology for creating services and products that "sense users' feelings" in the future. Measuring emotions in our daily lives is a step toward creating a world that "sense" our feelings. For example, we can watch over not only our physical condition, however it also includes stress and other aspects of our mind.