The characters are supposed to be based off the characters from the Sven Coop (Half-Life Coop) Uboa maps.
It took me like 10 - 20 minutes to model them.
UPDATE:
I searched that "Juuni Taisen" shit up, and I'd like to say that I'm disappointed in how all the characters look like they were pulled straight out of a BDSM furry convention. You probably shouldn't be watching and reading stuff like that.