[nickjr]

A future update (JP got this earlier this month) should let us skill up the sticker girls (with the original skills, so including all event forms except for NY Mitsuki) via the High Metal/Jewel Dragons. If you want to skill up the sticker girls and don't want to run anything else and/or you need your sticker girls skilled up ASAP, go for the AB Collab (and also gofor it if you want to skill up the other monsters who have skill fodder in this collab), but otherwise you don't need to use this collab to skill up the sticker girls since eventually their skillups will be relatively easy. ^^

Sticker girls = Mitsuki/Ruka/Kano/Fuu/Kurone