A doctored version of the common "Priority seat" sign has attained Urban
Legend status and a mention on Snopes.
http://www.snopes.com/photos/signs/metro.asp

It is hard to believe that people could think this was a real sign, although
it is well made. Maybe the film "Lost in Translation" is partly responsible
for making people believe that nothing is too bizarre in Japan.

-- 
Dave Fossett
Saitama, Japan