South Korea and Japan in March 2016 and I would like to know if I am able to take chocolate and toffees with me from England to eat while I am there.
Yes, you can. I'm not aware of any country in the world that does not permit importing (commercially manufactured) chocolate and toffee.
That said, I'm not sure you need to, since high-quality chocolate is very easy to find in Japan and Korea, with wide selections available in any convenience store. Sure, it's not going to be exactly the same as in the UK, but that's one of the joys of travel!