IT might be the unlikeliest instructional video ever, but footage of two Japanese amusement park executives demonstrating how to "scream inside your heart" to avoid spreading Covid-19 while on a roller coaster has been a roaring success.

It features the executives, one in a full suit and tie, and the other in a shirt and bowtie, sitting stiff-backed and straight-faced in silence, with the only sounds coming from the whipping of the wind and grinding of the roller coaster.