What is this Doc Tear Popper MAGES is looking for? in Hyperdimension Neptunia Re;Birth, MAGES asks the party if they know were she can find Doc Tear Popper. what exactly is it?
Doc Tear Popper is a drink and a play on the name Dr. Pepper.

the character MAGES, like other human characters in the series, represents a real world games company, in this case 株式会社MAGES. one of the known games which ties into MAGES's own appearance is Steins;Gate which in the anime had product placement featuring the drink Dr. Pepper

 

I don't know however wether the obscuring of the name is some legal thing as Code Geass had it's Pizza Hut product placement removed in the English Release or if it's a joke like Vert's overheating in the original game begin a joke on the X-Box 360's initial cooling problems