Devero watches him don the boots, reaching in here and there to make sure Koumyou gets all the straps right. "You can break an ankle real easy in these," he warns him, an explanation for his fiddliness with them.

The remote is a simple affair, with just the one button to switch the boots on and off and a slider to increase and decrease the power to the magnets. "--And that's all there is to it," he says, getting to his feet and offering Koumyou his hands. "Ready?"