To evaluate the affective value of industrial products, such subjective evaluation methods as questionnaires are commonly used, even though they have some demerits such as linguistic ambiguity and interfusion of experimenter and/or participant intention to the results. We began our research to objectively evaluate interactive systems by quantifying sensations using biological signals to supplement the above questionnaire demerits. We utilize biological signals to estimate participant feelings of relaxation, comfort, and excitement, which are considered positive sensations. First, we focus on a positive and dynamic feeling called “wakuwaku.” We construct various systems to evaluate affective values to derive wakuwaku feeling using biological signals and clarify the relation between the wakuwaku feeling and biological signals. Then we applied the obtained methods for wakuwaku feeling to evaluate kawaii feeling derived from various stimuli. Finally, we found that kawaii stimuli can be classified into exciting kawaii and relaxing kawaii.