If l33t is an English phenomenon mainly among Geeks, “Gal-Moji” (“Moji” = letters) is the counterpart for Japanese cellphone users, especially teenaged girls.
As with leetspeak, Gal-Moji users replace a standard Japanese character with a different but similar-looking character. This is made more chaotic, however, by the fact that the Japanese language has 3 different character sets (Hiragana, Katakana and Chinese-origin Kanji), along with the Roman alphabet and Arabic numerals, the total number of which is well over 3,000 characters. Characters not used in Japanese writing such as letters from the Cyrillic and Greek alphabets are even used.
Here is a sample from the Gal-Moji “dictionary” from Wikipedia. The Hiragana on the left (original Japanese characters) can be replaced with other similarly-shaped letters.
Similar shapes? For me, it is really hard to guess the target letter by looking at the letters on the right.
Kanji are morphed like this:
Gal-Moji was a social phenomenon in around 2002, when the mass-media portrayed it as a weird fashion of the younger generation. They are used less frequently than before, mainly because most cellphones now have their own original pictogram characters (e-moji, emoji) allowing people to express their emotions more easily. But you can still happen upon Gal-Moji in many places on the web, especially on mobile websites for young people.
In popular lore, the use of these secret languages was to show unity, to strengthen the concept of belonging to a group of friends, and to hide one’s communication from adults.
See also:
Gal-Moji Wikipedia [J]
Gal-Moji Converter [J]
“www” has another meaning in Japanese Web
Was surprised to read here that the most popular community on mixi is the one about emoji with about 460,000 members!
http://www.mobinode.com/?p=393#
Internet culture really is different here in Japan.
ASCII art is another tech otaku culture phenomenon that I’m sure must be bigger here than anywhere else. You can even buy books on emoji and ASCII art.
It’s interesting what people find interesting.