That is nice, but it is not the main reason for safer eggs in Japan compared to the States. The biggest difference is that eggs in Japan are usually not refrigerated either in transit, or the store, or even at home. There are a number of benefits from not refrigerating your eggs. They have longer shelf life. They never "sweat" on the outside of the shell, resulting in an environment for bacteria growth. They don't take up space in your small Japanese fridge. But, if you buy eggs that are already refrigerated, you need to keep them refrigerated.