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.
Women brought up within a Japanese culture will almost always say "Yes" to any invitation or request, and then simply not follow through. It's better to be polite in the moment, and be true to yourself later, rather than the other way around (as in Ameri