Standing out from the crowds of a myriad girl and idol bands in Japan can be a daunting task, but one such group, called "Kamen Joshi", seems to have found the answer -- by wearing masks.

The band, whose name means "masked girls" in Japanese, started three years ago.

The band's manager says putting on the masks began as a way to make them easier to recognise out of the multitude of other girl bands that dot the landscape of Japan's entertainment world.

Organisers say at the start of their career, they had trouble filling up even a 400-seater theatre.

Now, they have no problem filling up the Saitama Super Arena with over 15,000 fans, as they did at the end of last year.

"By wearing this mask, we become invincible. We can't live without it anymore. It is nearly as important as our own lives," said a Kamen Joshi Band member who goes by the stage name of "Moa Tsukino".

The band, consisting of 18 members, is based in Tokyo but has performed all over Asia