I think you have to approach it as you would any other class. That is to say that you need to tailor your lessons to precisely the needs of the class. So this means making a detailed Needs Analysis
of the class before going any further.
Once you have that you can sort out the syllabus and lessons to suit. Of course when you get down to the lesson level, you'll need to make sure the topics covered are suitable in both level and content to the class: many Western 12 year olds are interested in pop music, blockbuster films, television and so on with a burgeoning interest in fashion and sport. Does this apply to the children you will teach?
The basic principle here is to keep the lessons relevant to your class.