The main hall for a 6-month event held to commemorate the fiftieth anniversary of the City of Odawara as a modern municipal corporation. Due to limited time for designing, the architect had to use steel as the main structural material. But all interior and exterior walls were comprised of 305 paper tubes, each of which has a diameter of 53 centimeters, a thickness of 15 millimeters and a length of 8 meters. The toilet booths were built of paper tubes which had a diameter of 123 centimeters and a length of 8 meters. Transparent plastic hose was put between those tubes to seal up the structures through which streaks of light came into the rooms. For the main gate of the event venue, paper tubes were used as structural elements together with newly developed joints.