To go Pucca is to go madly in love with someone, even if the desired object does not like them back. Usually applies for females, especially if they are energetic, athletic and feisty. Comes from the Korean character Pucca, who falls in love with a ninja boy who does not reciprocate the affections.
Girl # 1: What's wrong with her?
Girl #2: Ever since she saw Drake from P.E., she's been going Pucca.
Girl #3: I wonder what I should wear if we get married???
Boy #1: Dude, this chick named Carly keeps tagging around so much, I swear she's crazy.
Boy #2: Didn't she try to beat up anyone who attacked you during that food fight a day ago?
Boy #1: Yeah....
Boy #2: I hate to be the one to tell you this, but I think Carly has gone Pucca all over you.
Boy #1: WHAT?!
For someone to go Pucca is not something to be taken lightly.