It took me a bit to confirm my suspicion about who this is, since I haven't watched this anime recently, but the character is called Accelerator and appears in a show called "A Certain Magical Index (Toaru Majutsu no Index)." Here's a link to info about the character if you are interested:
http://anidb.net/perl-bin/animedb.pl?show=character&charid=10527I imagine that character was used for a credit page because he's a favorite character of one of the admins at the site here, even though it's not a character from Get Backers.