Beckii Cruel - a young lady at the age of 14 gained popularity from the videos that she posted on YouTube of her dancing to JPop and anime tunes.
Today she performed at the Enta Matsuri in Akihabara where 600 fans showed up to egg her on.
An example of one of her YouTube vids below.
Fellow Brit Beckii became so popular over here that shes even got a DVD coming out in December which is currently up for pre-order at Amazon - PV for the DVD below.
More pics of Beckii dancing at today's event at Sankei.