The anime adapted from the manga remake version of the Korean webtoon "A Simple Thinking about Bloodtypes" involving the faceless and nameless characters of four different blood types to discuss about popular anthropomorphized blood types (the stereotypes about the blood types) in Japan and Korea.
Runtime: 2 minutes
Ketsuekigata-kun! - Blood type personality theory - Netflix
In East Asian countries, a person's ABO blood type is believed by many to be predictive of a person's personality, temperament, and compatibility with others. This is similar to how astrological signs are perceived as influencing factors in a person's life in other countries. One of the reasons Japan developed the blood type personality indicator theory was in reaction against ethnic stereotypes coming from Europe. The popular belief originates with publications by Masahiko Nomi in the 1970s. The scientific community generally dismisses blood type personality theories as a superstition or pseudoscience because of lack of evidence or testable criteria. Although research into the causal link between blood type and personality is limited, research does not demonstrate any statistically significant association between the two. Some studies suggest that there is a statistically significant relationship between blood type and personality, although it is unclear if this is simply due to a self-fulfilling prophecy. Recently, some medical hypotheses have been proposed in support of blood type personality theory.
Ketsuekigata-kun! - History - Netflix
The idea that personality traits were inherited through the blood dates as far back as Aristotle. Hippocrates also sought to link personality biologically, linking traits with the four bodily humors — sanguine, phlegmatic, choleric and melancholic. In 1926, Rin Hirano and Tomita Yashima published the article “Blood Type Biological Related” in the Army Medical Journal. It was seen to be a non-statistical and unscientific report motivated by racism.
Ketsuekigata-kun! - References - Netflix