Just as the mythical Emperor Shen Nung was said to have discovered tea in the 3rd millennium BC when some leaves fell into his cup, legend also has it that he invented popcorn tea unwittingly during a very early screening of Crouching Tiger, Hidden Dragon. Like most legends about tea, it can't be verified, but it's easy to think of the tea-rice combo as a godly accident up there with penicillin and post-it notes.
The ‘popcorn’ is actually popped rice: green tea is blended with brown rice grains, and some grains pop during the roasting process. It was originally reputed to be a paupers’ drink because the cheap rice was used to pad out the dearer tea leaves. But these days, Genmaicha appeals to all segments of society as an ‘everyday’ tea, especially as an after dinner drink.