Many instructors often complain that their students either cannot or do not want to discuss topics in class. For many students, confrontation, almost a requisite in many EFL textbook-style discussions, is something to be avoided, even if the topic is something they would truly enjoying discussing.
To overcome such a barrier when you have pairs discussing binary topics (e.g., "Which is better, a fork or chopsticks?" or "The kyoyobu system is not good for students."), have students flip coins or do "jan-ken-pon" (rock, scissors, paper) to decide who will take which side. In the above example, each pair decides who (A-san) will flip the coin. If A-san flips "heads" (or, on a 50 yen coin, the number or bangou side), A-san chooses "fork" (or agrees, depending on the question); if tails (the picture or e side), A-san chooses "chopsticks" (or disagrees). The discussion can now begin, with the coin taking the blame for the inevitable confrontation; true feelings (honne) are no longer threatened, so students can really enjoy attempting to fatally dissect each other's reasoning.
While slow students might have a hard time understanding this concept initially ("But, teacher, I hate forks!"), they do catch on quickly. Most students also enjoy tongue-in-cheek warnings not to blind themselves or others with stray coins, if that is the option you choose for deciding sides.