I feel kinda stupid for how long it took me to understand that the masks were song references, but then I redeemed myself when I noticed the Rin and Luka references.
Sakura no Ame or Sakura MikuYuki MikuLots of LaughMiracle PaintHatsune Miku no Shoushitsuclock lock worksSaihateRomeo and CinderellaUra-omote LoversHello PlanetWorld is MineBlack Rock ShooterWhite DoveTower of Sunz