Gouhou Lolita Syndrome
Gouhou Lolita Syndrome (more commonly called Lolisyn, occasionally written in English as Legal Lolita Syndrome, or abbreviated in numbers as 564) is one of those breed of metal idol groups. They mostly play shows with similar groups of that type - Zekkyou Suru 60-do, Next Shoujo Jiken, Guso Drop etc.
They originally formed from the remnants of a group called 〓しましまSPANK〓 and still perform their songs. They started with two members, Rina and Natsumi, who were in the group from 2013.8.1-2014.3.16. They then replaced them with two new members Hiro and Haru, who both started on 2014.3.13. They also have a 3rd member, Rinen, who is only 13, and so not legal, so when they perform with her (which is rarely) they call themselves "Gouhou Lolita Syndrome Kai". They also sometimes play with a live band called Slipperknot
They've released one single "four session" in 2013 which contains "four session", "My Precious Life", and "Kyoakunaru Croissant". And also a limited mini-EP "LEGENDE" which contains those three songs, three 〓しましまSPANK〓 songs and the overtures of both groups.
Their live performances are really fun, and their fans are pretty crazy, and yes, Lolisyn are the kind of group who will stand on your face in chekis with you if you ask them to.
Most vids online are of the old line-up, but this is one of their current lineup performing Croissant, their most poppy song...
And here's one of Rinen's debut performance:
And here's one of the old line-up performing with that live band: