100% Orange Juice

Store Manager (Banned for Life) appears on Practice Field, Space Wanderer, Pudding Chase, Christmas Miracle, Highway Heist, Tomomo's Abyss, White Winter, Farm, Sweet Heaven, Treasure Island, Treasure Island (Night), Icy Hideout, Santa's Workshop, and Ocean Dive.
Shifu Robot (Full Metal Brother) appears on Planet Earth, Warfare, Sealed Archive, Clover, Star Circuit, Training Program, Vortex, Starship, and Shipyard.
Flying Castle (Moving Castle in the Sky) appears on Lagoon Flight, Sunset, Night Flight, Frost Cave, Witch Forest, Sakura Smackdown, Over the Sea, Dark Citadel and Beginner Town.

A general strategy for bosses, aside from grinding these out in singleplayer if you'd like, is (unless you can pull off character-specific shenanigans, let's say you just pop off as Tomomo and roll 8 against a boss) to wait until the boss drops to 1 health, then either attack a player on top of a boss space (if they live) or just do your best to land on a boss space before anyone else does.

Additional tip: in singleplayer, you can hold Ctrl and Shift to speed things up exponentially. (Especially if you're not on Speed 4. But why would you not be on Speed 4?)