Manufacturers even market a wide variety of blood-type specific products, including calendars, chewing gum, colas, and condoms.

In Japan, a person’s blood type or ketsu eki gata is a popularly used to determine a person’s temperament, much the way Americans use astrological signs.

The difference is that the Japanese take blood types very seriously.

Japanese dating services use blood types to make matches. High school students exchange blood types by way of introduction.

Sports card include athletes’ blood types prominently alongside more traditional sports statistics.

Since the Institute’s founding, interest in ketsu eki gata has continued to grow.

It has been used to hire employees, divide labor forces into blood-type appropriate roles, broker marriages, and even dictate child-rearing techniques.

It’s use has become so widespread, in fact, that some people have reported being discriminated against because of their blood type.

People with blood type B were just the opposite – easily roused to anger and unintellectual.

Furukawa published a series of articles and books, called “The Study of Temperament Through Blood Type,” which the public gobbled up, despite a complete lack of hard evidence.

Interest in ketsu eki gata waned after Furukawa’s death in 1940, but was revived in 1971 when journalist Masahiko Nomi expanded on Furukawa’s theories in a best selling series of book, “Understanding Compatibility from Blood Types.” The new theories associated some blood types to academic success and different types of crime.

After Masahiko Nomi’s death, his son Toshitaka Nomi founded “Ketsueki-gata Ningen-gaku Kenkyusho,” the Institute of Blood Type Humanics.