Among other superstitions the Japanese have embraced, one of the most peculiar is blood types. Quoted from informationism.org
Blood type theory is widely popular in women's magazines as a way to gauge relationship compatibility with a potential or current partner. Morning television shows feature blood type horoscopes, and similar horoscopes are published daily in newspapers. Though there is not a proven correlation between blood type and personality, it has still remained in the many matchmaking services that cater to blood type. In this way, it is similar to the use of astrological signs in the west, which is also popular in Japan.
What's Your Type?
As of this writing, I have no idea what my blood type is. Most foreigners don't. Nevertheless, some businesses go so far as to screen potential employees based on unscientific data.
Type A Reserved and prone to worry, sensitive perfectionists such as Britney Spears and Adolf Hitler.
Type O Decisive, self-confident, curious, and ideal for sport, including Elvis Presley and the Queen.
Type B Cheerful caring, flamboyant free-thinkers such as Jack Nicholson.
Type AB High-maintenance, distant, suited to arts, such as Mao Zedong.
Regardless of the hearsay, knowing that the Japanese have an interest in blood may prove useful in effective witnessing. Hebrews 9:14 How much more, then, will the blood of Christ, who through the eternal Spirit offered himself unblemished to God, cleanse our consciences from acts that lead to death, so that we may serve the living God!