The risk of large buildings defeated by a quake obviously isn't zero, so if there is somehow dozen football fields worth of solid and flat land(in Japan!?) next

The risk of large buildings defeated by a quake obviously isn't zero, so if there is somehow dozen football fields worth of solid and flat land(in Japan!?) next to where you would be, it makes sense to run out to there and see if the building holds. If that isn't available, the next best option is to get down and hide under furniture to protect yourself from debris. Glass windows could break and sound deadening parts or small concrete pieces on the ceiling could fall during one, getting hit by those can be fatally uncomfortable, but they're not machine gun bullets and just ordinary tables should be able to stop a lot of them.