Bandai Namco released the official THE iDOLM@STER: Cinderella Girls LINE animated / voiced sticker set for 100 coins. You can get the sticket packages only in the selected countries like Japan where you can also buy it for 240 Yen (with tax) instead of the coins.

The package includes 24 cute stickers with the main characters of the IMAS CG with SD character style. You can find it in here: