Costumes are sets of outfits, accessories, and hairstyles that characters can wear. These costumes are visible in Solo, Multi, Cheerful, and Challenge Lives if there a 3D MV for that song. Characters can be seen wearing their costumes in the MV viewer.
Costumes can be unlocked by owning certain 4☆ cards, completing parts of the Premium Mission Passes, spending crystals in Crystal Shop, rolling in Premium Gachas. Costumes are unlocked for all characters when the Premium Mission Passes are completed, when the costume purchased in the Crystal Shop, or when rolled in Premium Gachas. Costumes associated with a 4☆ card are only automatically unlocked for the character the card is of. The other characters can unlock the costume after purchasing it in the Costume Shop.
All costumes have 4 variants; each variant is a recolor of the first variant. Some costumes, like those purchasable in the Crystal Shop, come with all variants unlocked for all characters. Other costumes, such as those purchasable in the Costume Shop once a 4☆ certain card has been acquired, require Master Rank 1, 3, and 5 for variants 2, 3, and 4, respectively. Like when the card is first acquired, these variants are automatically unlocked for the character the card is of.
Some costumes come with unique accessories and unique hair, which may only be worn by certain characters. For example, Coffee Cup Balloon is a costume with unique accessories and unique hair for Kusanagi Nene. The hairstyle is unlocked when the card it is associated with is at Master Rank 2.