In Japan, people believe in the theory that “ketsueki-gata” (blood type) is crucial for the personality, the relations to others and the temper of every person. Similar to astrological beliefs and the 12 zodiac signs which predetermine a person’s nature, emotions, relations, etc., this belief in the importance of blood type has led to discrimination and serious rearrangements at work, school, sports and in many other important aspects of the lives of Japanese people.
In Japan it is very common for a person to be placed in a certain group at school, positioned in a certain sports team, offered a certain job position or denied it or to be matched to someone romantically only because of their blood type.
There is even a term known as “bura-hara” (blood type harassment) which is the term for people being bullied, fired or ditched by their loved ones just because of their blood type.
The fun aspect of “ketsueiki-gata” is that Asian users actually get to add their blood type in the “About me” personal information section of their Facebook profiles, and in most video games you get to pick the blood type of your character .
The importance of ketsueki-gata for the Japanese is also the reason why you can expect to watch a blood type horoscope in morning shows in Japan instead of an astrological one.