I also thought they were hot and cooked when I first went by the place and didn't look carefully. But the small spot that was reformed to put the machines in was too tiny to have a kitchen in back (though this being Japan, you can never be sure about "too tiny"), plus there was no cooked gyoza odor in the air (which would've made my shirt wet from the drool). So, I was forced to go back and investigate, for the sake of the neighborhood of course.