Apparently Japanese telecoms companies are trying to convince the world that written Japanese does not already have enough characters.
These additional characters are used to depict emotions and other symbols in a similar manner to SMS emoticons.
Rather than being combinations of characters, such a 
, which is entered as a : followed by a ) , to represent a smiley in the Latin character sets, there is a movement to create a whole range of new symbols, into Unicode, which include colour and animation.
At present, they are exchanged in SMS messages by using privately agreed character codes, but there is pressure to add these new emoji ideographs into the Unicode specification.
Some of the key problems that adding Emoji to the Unicode standards would present include:
- Adding shapes to Unicode, which has carefully remianed indepentant of how glyphs are drawn
- Adding colour requirements to Unicode, which again has had no logical need to specify colours for characters
- Adding the concept of animation definitions to characters, which is well outside the range of a character set definition
