Tokyo Toilet project location, public toilets using electrically opaque glass.

#8: Yoyogi Fukamachi Mini Park

Transparent Toilets as Beautiful Lanterns


Location #08 is at 1-54-1 Tomigaya, Shibuya. It's in a small park across a busy street from the west edge of the large Yoyogi Park.

Shigeru Ban, the designer of both this and location #07, wrote "There are two things we worry about when entering a public toilet, especially those located at a park. The first is cleanliness, and the second is whether anyone is inside. Using the latest technology, the exterior glass turns opaque when locked. This allows users to check the cleanliness and whether anyone is using the toilet from the outside. At night, the facility lights up the park like a beautiful lantern."

Visiting the Toilet

The location is one of the project's two "Transparent Toilet" facilities on which the international media has focused. The walls and doors are made with smart glass, a concept that has been around since the 1980s.

Smart glass contains a liquid crystal film which normally is opaque. That film is between two layers of glass, with transparent electrically conductive film on both sides of the liquid crystal layer. Each panel is a large capacitor.

The liquid crystal film is normally opaque because the crystals are randomly aligned and scatter light. Applying a voltage to the conductive films on both sides causes the crystals to align, making it transparent.

When I arrived, the universal toilet at left was in use, a woman was entering the woman's toilet at center, and one of the many maintenance staff was cleaning the men's toilet at right. I sat on a park bench and waited.

Overview of Yoyogi Fukamachi Mini Park Public Toilet.

The "fail safe" design of the system means that breaking a connection or disconnecting the electrical power causes the film to revert to its normal opaque state.

On my previous visit, international media had reported that the entire Tokyo Toilet project was shut down. The problem was limited to a smart glass problem at just one or possibly two sites.

The universal toilet and the women's toilet were soon vacant, while the men's was still being cleaned.

Men's toilet still opaque and being cleaned, universal and women's are vacent.
Yoyogi Fukamachi Mini Park Public Toilet.

I used the universal toilet.

Entering the universal toilet at Yoyogi Fukamachi Mini Park.

Inside with the door pulled shut but not latched, the smart glass remains active and therefore transparent.

The door is unlatched, so the glass is electrically powered and transparent.

Turning the door's latch handle, which is located near the floor so everyone can reach it, locks the door and interrupts the electrical power that was keeping the liquid crystal film transparent. The liquid crystals revert to their normal random orientation, scattering the light and making the walls translucent, passing scattered light, but not allowing you to see out or in at all.

The door is latched, so the glass is unpowered and opaque.

All of the Tokyo Toilet project locations have Washlet toilets, the controls for the built-in seat heater and bidet functions are mounted on the wall within easy reach.

Washlet control panel.

The ostomate fixture is next to the sink.

Sink and ostomate fixture.
Ostomate fixture.
Drop-in charger for a child.

The staff member was finished in the men's toilet, and now cleaned the doors and handles on all units.

Tokyo Toilet project cleaning staff at the Yoyogi Fukamachi Mini Park Public Toilet.

The men's was now spotless and ready for a user.

Yoyogi Fukamachi Mini Park Public Toilet.

There's a brief explanation of how the glass switches. The system made me feel very comfortable, with no worry that someone was going to see inside while I was using the toilet.

Japanese and English explanations on the exterior of the door.

Moving on to the Next Location

Locations #06, #07, and #08 are close together along the west edge of Yoyogi Park. Fukusen-ji, a Buddhist temple, and Yoyogi Hachiman-guū, a Shintō shrine thought to enshrine the kami Hachiman, provide interesting things to see between #06 and #07. They're close to the Yoyogi-Hachiman Station, OH 04 on the Odakyū Odawara Line, and the Yoyogi-kōen subway station, C 02 on the Chiyoda Line.

Next❯ #09: Urasando

Tokyo Toilet — Overview and Introduction
#1: Sasazuka Greenway #2: Hatagaya #3: Nanagō Dōri Park #4: Nishihara 1-chōme Park #5: Nishisandō #6: Yoyogi Hachiman #7: Haru No Ogawa Community Park #8: Yoyogi Fukamachi Mini Park #9: Urasando #10: Jingūmae #11: Jingū Dōri Park #12: Nabeshima Shōtō Park #13: Higashi Sanchome Park #14: Ebisu Park #15: Ebisu Station #16: Ebisu East Park #17: Hiroo East Park

Other Toilets in Japan: