In seven grade? Hmm, why only 'Bakura'? Did your friend started calling you by this name or something? Or is it just that you came up with that name yourself so that it can be used online?
My case was totally different. It was like..the time of my first name change. I was searching for a new name for this account and just happened to come across a philosopher named 'Derozio' in my History book. That was it. I picked up the name and started using it everywhere. Kinda weird that I found it in a textbook 'o mine, yeah. xD;