Copyright: nan-j
Nan-J (なんJ) is short for Nandemo Jikkyō Jupiter (なんでも実況J(ジュピター)), one of the boards of 5channel (formerly known as 2channel), a Japanese BBS website.
Anons of the board are portrayed as strange-looking humanoid creatures named Yakiu no Oniichan (やきうのお兄ちゃん, "Big-Bro of Basebaww"). They like baseball and have a legend that they were settled in Nan-J when they destroyed the natives (原住民 Genjuumin) who originally existed.
In contrast to other Japanese web communities where Standard Japanese is chiefly spoken, Mōko-ben (猛虎弁, "Fierce Tiger Dialect"), a peculiar wording style based on Kansai dialect, is deemed standard in Nan-J and its derivatives or culturally-influenced communities. This originated when folks of the board played Hanshin Tigers fans sarcastically.