Japanese Women's Office Sandles

I previously mentioned my observations of Japanese lady's office wear in entries about Denji Boushi Aprons and Uniforms and after getting some more information about the footwear from A I wanted to expand on that. When I arrived for my assignment a pair of steel toe safety sneakers were ordered for me (I couldn't find a photo ugly enough to do them justice), I wear them when I attend a build which hasn't been very often. Many of the other women, including the OLs, have the same safety shoes but some also have sandals that they change into after arriving in the locker room each morning.
I had assumed that these sandals were part of the uniform, but A informed me that they are not uniform but only a preference. They are called "Nurse Shoes" (a katakana word so think English with Japanese intonation) and are meant to eliminate the strain of wearing heels.