This isn't your father's Monkey Ball. Actually, maybe it is.
For a limited time, Sega is offering "Adult Map" download codes for those who purchase Super Monkey Ball: Tokumori Asobi-ta! for the PS Vita. In it, you can roll all over bikini model Yukie Kawamura. In some parts, the model's breasts protrude from the map and players must navigate them.
Kawamura recently featured in a clip that showed her playing the PS Vita title while bouncing around. This sounds less like Monkey Ball, and more like monkey business.