wait , how do you buy them?

Go to the avatar shop, under the shops tab. All the monthly items are sold under the "monthly items" category. Fill in the number of whichever items you want, and click complete purchase.

All monthly items can only be bought using diamonds.

-stifles a sigh when she realizes she didnt say anything-

I was lucky enough to be given the complete set's of the Monthlies by Icekitsune, and I'm super grateful anf find it surreal I get every item of my favorite Month. Thank you, thank you artists, love you ^-^