For Japanese teenagers and adults who wont respond it's usually an insecurity issue not a language or teacher issue. They are concerned what others will think of their answers or they simply just aren't imaginative enough to come up with one.
If you have a class like this, limit their response selection to just 2 or 3 until they feel more comfortable. Or, you can give them responses (have flash cards for the target language and they must reply with whatever flash card they have.)
Ex: target language - have to/ What do you have to do tomorrow?
Give each sudent one or two cards with chores. Then tell them this is what you have to do tomorrow. Then proceed to practice the language in whatever method you see fit. You can build slowly away from the cards as the activities progress.
Once they are speaking and have got a good grasp of the language maybe you'll get some non-scripted answers.
I hope that helps.
Mark
www.mes-english.com