I have no idea about who きゃりーぱみゅぱみゅ is. Seriously, I don't. I can tell that she is a type of J-Pop star. I can tell that she's likely, too, a corporate-made star, and she fits into the mold of Japanese "cuteness".
Her songs aren't too masterful, and her choreography is ... well judge for yourself:
Here, in Candy Candy, きゃりーぱみゅぱみゅ tackles the difficulties of running in a sailor-moon-hair wig and the really difficult English words of candy, sweetie, girls, love, and chewing.
She didn't even sing anything in this one! (Or really dance, either.)