YS-3 is an interactive animation device. This device makes it possible to display animations with an actual sense of depth and let a viewer control developments of animations. It has seven plastic displays and each display is inserted into different level of tower-style device. With this structure, all animations on different displays are stacked like multi-layered animations. There is a space between displays. So, it can provide visual experience that cannot be attained by flat-style displays. And a viewer can change the composition of displays in the device. What decides developments of animations is this composition. In this paper, we discuss about effective interaction design and animation design in YS-3. These methods will lead to contents design in visual media different from flat-style display such as a TV screen and a screen.