Japanese warning signs are very different than warning signs in other parts of the world, because they usually contain a visual and easy to understand reason why something is dangerous or not allowed.
The Smileys(Emoticons) are used very often in the sentences of e-mails. They started in USA where the internet had also started of course. In Japan, the Smileys(Emoticons) grew in different manner from U.S.A. Now, there are several kinds of them.
Vintage Japanese WWII Air Raid Defense Posters made in 1938, by the Japanese Red Cross working with government authorities to create a series of posters to teach the public about the new Anti-Aircraft Defense Law, which was enacted in seeming anticipation of air strikes following the outbreak of the Japan-China War (1937-1945).