This South of Midnight Floof Bundles locations guide will run you through where to find them all, so you can get all the upgrades you want. You start collecting Floof Bundles in Chapter 2 ...

Talk to Fresnay beside the Padro merchant, and Surprise-O-Matic machine on the western side of Florawish town to start the The Floof Triplets Photo Investigation quest in Infinity Nikki.