There is no connection between Taekwon-do and Nunchaku. Taekwon-do is is unarmed Martial Art which comes from Korea and Nunchaku is a weapons Martial Art from Okinawa which is an Island 175 miles from Hong Kong.
We use nunchaku's in extra training before any taekwon-do class. The students train with a foam/rubber nunchaku's myself and experienced students trains with wooden nunchaku's. Also we include the nunuchaku's in our displays. So that we do not confuse other taekwon-do schools about out use of nunchaku's the students wear our own design of martial art suits and we wear a diferent type of belt.