Are These UFOs Flying Over An Industrial Plant In Osaka, Japan?

[youtube https://www.youtube.com/watch?v=89lMFrp_AJg&w=560&h=315%5D

This 2-minute video features a cluster of UFOs floating around Osaka, Japan. People are speculating that they are quadcopters programmed to fly around in formation. If that’s the case: Why? What do you think?