The second big factor in Mister Donut's success in Japan I would have to say is the "San Francisco Chinatown" or "Mister Yamucha" in Japanese menu selection. This turns a donut shop into a restaurant and the Chinese ramen and yamucha goes surprisingly well with donuts. The most important aspect of this is that parents can go to a Mister Donuts with their kids, get some real food, a donut and good coffee (with free refills). You clearly see more people enter Mister Donut shops as groups and stay longer than you would otherwise. 飲茶
Photo is a web capture for explanatory purposes, copyright belongs to the company.