Many of the nonverbal proverbs used in interpersonal communication are related to the eyes, such as “the eyes speak as much as the mouth” and “the eyes are the mirror of the soul.” This is because it has been recognized for a long time that the eye is an interface that easily reflects human affects, and it serves as a clue for conveying affects and feelings in communication. In particular, the eyes that human perceive during communication are considered to estimate others’ affects by integrating not only global cues such as “gaze” but also local cues such as “pupils.” Thus, the impression by conveying affects from the eyes is called “eye appeal.” This paper describes an approach of minimal design that eliminates the gaze and focuses on the pupil, which has the minimum required appearance and movement. Furthermore, we will introduce a pupil response robot called “Pupiloid” that expresses human pupils and eye appeal communication systems and discuss future communication designs that include pupils.