This one drives me nuts. 'Natural' is a marketing term. It has no legal definition in the context of matcha. A product can be 'natural' and still be full of synthetic additives. Organic, on the other hand, is regulated. In California, the Department of Public Health can fine companies for misleading 'natural' claims, but it's not the same as organic certification.

If you see 'natural' on a matcha tin, don't assume it's organic. Look for the seal. If it's not there, it's just a word.