Metal groups such as Pantera and Lamb of God are being outsold by three small Japanese girls on iTunes.
Babymetal's self-titled first album sits at No 3 on the list of iTunes metal albums and the video to their single "Gimmie Chocolate!!" has almost three million views on YouTube.
Their music is a mix of Japanese pop and heavy metal which has been dubbed kawaii metal (cute metal) by their record label.
The band members originate from Japanese pop group Sakura Gakuin, but formed a sub-unit of the band and called it Babymetal in 2010, despite having no idea at the time what metal music was.
Sakura Gakuin members are only allowed to be in the group until they finish junior high school, so when the band members leave school they also "graduate" from the band.
Thus when the lead singer, known as Su-metal, and backup singers Moametal and Yuimetal came of age they went full-time with Babymetal.
Other hits from the group include Ijime, Dame, Zettai (loose translation: no, more, bullying) and Headbangeeeeerrrrr!!!!!.
The music video for Gimmie Chocolate!! is nearly impossible to describe but equally as hard to take your eyes off.