First, I need to verify if "Porcupine J Cup" is a standard term. If not, I should look up any product with that name or similar to get accurate details. Since I can't browse the internet, I have to rely on existing knowledge. Maybe "Porcupine" refers to a style with multiple small support points, like a Porcupine bra, which I know can have adjustable straps or multiple closure points for support. J Cup is likely a size in the Japanese bra system, corresponding to different coverage levels.