Do I need a Chinese transit visa for a stopover of 12 hours?

My passport is Bangladeshi, but I`m living in Japan with permanent visa. I`m going to Dhaka from Osaka. My flight is from Kansai International Airport (KIX) to Kunming, but I have to change my flight in Kunming. I have to stay in Kunming Airport more than 12 hours. Next flight from Kunming to Dhaka. Please confirm me