Fukushima plate is a common ceramic plate with integrated organic LED rings that respond to the level of radiation in food. Everyone appreciates their health in different ways, and therefore on the underside of the plates can be adjusted as a large dose of radiation you are willing to let into your body.
If nothing on the plate does not appear - your food is completely safe. If it appeared one white ring, then your dish slightly elevated radiation levels, but nothing to worry about. Two glowing ring warn that your food is not really as good as it looks. And if there was a red ring - dose radiation plate exceeds the level you set, and can be dangerous to health. These dishes are made in Japan.