In Japan, one of the first questions you might be asked is: 'What's your blood type?' It's not for medical reasons. It's because many Japanese people believe blood type determines personality, much like we think about zodiac signs. Strange? Maybe. Fascinating? Absolutely.
血液型 (Ketsuekigata): The Blood Type 'Zodiac'
血液型 (ketsuekigata) literally means 'blood type'. In Japan, this belief is so widespread that you'll find blood type references everywhere: in manga and anime character profiles, dating apps, job interviews (illegally, but it happens), and everyday conversations.
The theory gained popularity in the 1970s with Masahiko Nomi's bestselling book. It has no scientific basis, but it's deeply rooted in the culture.
Type A (A型): The Perfectionist
The most common blood type in Japan (about 40% of the population). Type A people are considered:
- Organized and methodical
- Sensitive and detail-oriented
- Anxious and perfectionistic
- Cooperative but reserved
- Punctual and reliable
- Tend to suppress emotions
Stereotype: The colleague who arrives 5 minutes early and has a perfectly organized desk. Best compatibility: A and AB.
Type B (B型): The Free Spirit
About 20% of Japanese people. Type B has the worst reputation in Japan (unfairly):
- Creative and original
- Independent, sometimes selfish
- Direct and honest (too much, some say)
- Unpredictable and spontaneous
- Passionate about their interests
- Difficult to control
Stereotype: The artist who does what they want and says what they think. In Japan, 'you're type B' can be a veiled insult. Some people avoid dating type Bs. Best compatibility: B and AB.
Type O (O型): The Natural Leader
About 30% of the population. Type O is viewed positively:
- Confident and determined
- Sociable and charismatic
- Optimistic and resilient
- Competitive but loyal
- Sometimes insensitive to details
- Tend to dominate conversations
Stereotype: The team captain, the one everyone naturally follows. Best compatibility: O and AB.
Type AB (AB型): The Enigma
The rarest, only about 10%. Type AB is considered mysterious:
- Rational and analytical
- Adaptable (have traits of both A and B)
- Eccentric and unpredictable
- Genius but detached
- Difficult to understand
- Diplomatic but elusive
Stereotype: The brilliant scientist nobody really understands. Fun fact: many famous serial killers in Japan were type AB, adding to the mystique. Best compatibility: Compatible with everyone, truly intimate with no one.
Summary Table
| Type | Positive Traits | Negative Traits | In Japan |
|---|---|---|---|
| A | Organized, reliable | Anxious, rigid | ~40% |
| B | Creative, honest | Selfish, unreliable | ~20% |
| O | Leader, optimistic | Insensitive, arrogant | ~30% |
| AB | Genius, rational | Cold, unpredictable | ~10% |
血液型ハラスメント (Bura-hara): Discrimination
The belief is so strong that there's a term for blood type discrimination: ブラハラ (bura-hara), from 'blood harassment'. Some employers ask about blood type in interviews (illegal since 2011), and some people avoid relationships with certain types.
Type B faces the most discrimination. There have been cases of school bullying based on blood type. It's a dark side of this seemingly harmless belief.
In Pop Culture
Blood types are everywhere in Japanese entertainment:
- Character profiles: every manga/anime character sheet includes blood type
- Idols and celebrities: blood type is standard info in bios
- Horoscopes: daily blood type horoscopes exist
- Products: chocolates, drinks, and gadgets 'for your blood type'
- Video games: The Sims Japanese version includes blood type
Useful Kanji
How to Answer When Asked
If a Japanese person asks 血液型は何ですか？(Ketsuekigata wa nan desu ka? - What's your blood type?), you can respond:
- A型です (A-gata desu) - I'm type A
- B型です (B-gata desu) - I'm type B
- O型です (O-gata desu) - I'm type O
- AB型です (AB-gata desu) - I'm type AB
- わかりません (Wakarimasen) - I don't know (perfectly acceptable)
Conclusion
The blood type belief has no scientific basis, but understanding it helps you better understand Japanese culture. It's a great conversation starter, a way to connect with Japanese people, and a window into how social psychology works in Japan. And if you're type B... good luck.
