It's not actually a character in Japanese or Chinese I don't think. There is some grammatical information here:
http://dic.nicovideo.jp/a/%E3%82%A2%...81%A3%E8%A8%98
And there's also some mention of it in the JP wiki
http://ja.wikipedia.org/wiki/%E3%82%...83.8C.E6.99.AF
*edit* when I try to paste it into the forum box, it kills the post, but you can see it at the link.