Those who pass the test are also called "sammeliers," a play on words combining "sa" for tea (茶, also pronounced "cha") and "sommelier," the French word for wine steward.
According to the NIA's website, over three thousand instructors and advisors have been certified throughout Japan. These "green tea stewards" ply their trade at restaurants, inns, trade shows and other events.
Tea sommeliers are also in demand at schools, where they teach children the art of preparing the perfect cup of tea. Not that making tea is that complicated—it's just that even in Japan, a lot of kids nowadays think of green tea as something that comes in a bottle from a vending machine.