Yoshimi Fujiwara? I doubt that's your real name, but I guess I can call you whatever you like. Kristine (assuming that is your name), Yoshimi-chan, Fujiwara-san, Yoshi-tan, I like nicknames.
I don't really have a cosplaying code name, but I usually go by the alias Kaji Motomiya. Other than that, I have people call me "Jamie."