The annual competition for the summer's hit drink is as fierce as usual, and all the major manufacturers have their contenders. Will it be Asahi's new Red Eye in a can? Or Pepsi's latest oddity, the shocking-pink Salty Watermelon soda?

According to the morning TV show “Non Stop!,” the winner may just be a dark horse: amazake.

Though it literally means “sweet sake,” this fermented rice drink is actually alcohol free and has been around for centuries. In the Edo Period, it was commonly drunk to ward off the dreaded natsu-bate (summer heat fatigue). Apparently the combination of vitamin B and glucose provides an immediate jolt of energy. The rich ate eel; the rest drank amazake.