The translation posted above is pretty accurate. Some young guy is playing Brawl online and his family is watching. He chooses Kazuyuki from the list and gets his butt kicked. At the end the little kid asks who Kazuyuki is, and we se s/he is a trap!
I'm not sure about this bit, but I think Kazuyuki is something of a joke name. I can only think of guy's names starting with "kazu", but "yuki" sounds really feminine to me.
From looking at this commercial, people are probably going to assume Brawl has voice chat. AFAIK there is none, so I think they should've done it a bit differently. =/







