In Japan, kale was used more for its aesthetic qualities, as ornamental plant. While traveling through Japan, you may see it in the gardens, especially during winter, like this white-violet flower bed from Narita-san Shinshō-ji.
During the World War II, a drink made of kale became famous in Japan: called aojiru, it was invented by Dr. Niro Endo, who, in order to feed his family during that time of crisis, created a juice made of discarded leaves, most of them kale.
Interestingly, though, the drink was popularized again in 1983 by the company Q'SAI: a juice made entirely of kale, sold as a dietary supplement... Apparently it is good for the health, but it tastes so bad that it is sometimes used as a "penalty" during the Japanese TV game shows... (^_^)
EXIF info:
Nikon D90
Lens: 8-16mm F/4.5-5.6G
Focal Length: 8mm
Aperture: F/5.6
Shutter Speed: 1/800s
ISO Sensitivity: ISO 200