We report on the development of "Bouncing Star," a smart-ball system, and its applications as an entertainment system. The concept of a "smart-ball interface" is described. We then explain the interaction of the expressions of the ball that we produced. The Bouncing Star has been exhibited ten times, and over 10,000 people have participated in the exhibitions. We discuss the possibilities for a smart-ball interface in the future, based on the observations of exhibition experience. Straight move, (with and without spin) Ball is thrown, (with and without spin) Ball is caught, Bounce (on wall, floor)Interactions (lighting, sound, text/image and graphic interaction, haptic interaction, information processing, and wireless function)