Do i need to get Visa before traveling or i will get on arrival permit?

Hello,
I am a Bangladeshi citizen. I will be traveling Japan(Tokyo) by China Eastern Airlines & have two stops in China. The departure flight will stop over in Kunming & Beijing. The return flight will stop over in Shanghai & Kunming. All of the stop overs are less than 24 hours. I can see from this article that around 45 country citizens can get it on arrival but Bangladesh is not in that list. Now my question is do i need to get a transit G in my case or if i have to apply from before for this since i have a domestic flight. I heard that there is a provision of special permit for these case. Please confirm the process.