This project has been started questioning how to make various relationships between inside and outside. If there are one outer sphere and one inner sphere which share the same focal point, and then compose window connecting those to spheres, people can look outside standing on one point, which does not offer various visual relationships. However, once start rotating the inner sphere, people inside should move around to look outside, which results in interesting visual relationships between in and out. And if rotation takes place on several different planes, orientation changes dramatically, constituting complex and various visual relationships.