A UD Dry Toilet (Urine Diversion) is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. The exhibition focuses on how the toilet has changed our daily lives and discovers what the most environment-friendly and ideal toilet is. (Photo by Keith Tsuji/Getty Images)

An old squat toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A giant toilet model is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A gold toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

(Back L-R) Japanese astronaut Mamoru Mohri, Executive Director for the Miraikan and speaker Osamu Suzuki pose for group photo during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

An urine drainage pants is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

“Mark 5” a conceptual space toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A toilet decorated with crystal rhinestones is displayed with during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

Many toilets displayed with cartoon faces are seen during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A children toilet sets are displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

A cross section of moden toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)

An old toilet is displayed during the “Toilet!? Human Waste and Earth's Future” exhibition at The National Museum of Emerging Science and Innovation – Miraikan on July 1, 2014 in Tokyo, Japan. (Photo by Keith Tsuji/Getty Images)