Who is Babymetal? They're a trio of Japanese girls (Suzuka Nakamoto, 16, and Yui Mizuno and Moa Kikuchi, 15) whose fashion is partly inspired by goth and Harajuku styles, and whose music is a blend of synth-laden J-pop and seriously dark, thrashy metal (with the occasional dip into reggae). A prefab band constructed overseas, they released a self-titled debut studio album in February and charmed both Lady Gaga and U.S. listeners alike with tunes such as "Gimme Chocolate!!" and "Head Bangya!!