Transparent toilets have hit the Shibuya district of the Japanese capital as part of the Tokyo Toilet Project.
They are made of a completely transparent coloured material called smart glass. However, when a person enters such a toilet, the glass becomes opaque so no one is able to see the visitor.
Besides, the high-tech toilet also functions as a lantern to illuminate paths in parks during night-time.
The project, sponsored by the Nippon Foundation, and carried out by Japanese architect Shigeru Ban, aims to upturn stereotypes about public toilets being "dirty and smelly" places.
The solution solves two key issues - first, a visitor can see whether the toilet is clean inside and, second, whether it's busy or not.