Japan Culture: Understanding Japanese Blood Type Personalities

Similar to the Western horoscopes, the Japanese believe that a person’s personality is connected in some way to their blood type. Are you curious about what your blood type says about you? Let’s find out more about this curious blood type personality theory prevalent in Japan and other Asian countries.

Table of Contents

  1. Essential Background Information
  2. Japanese Blood Type Personalities
  3. Blood Type and Life Choices
  4. Blood Type Personalities in Japanese Media
  5. Summary

Essential Background Information

General Understanding About Blood Types

Blood types are influenced by the genetic code you inherit from your parents. Therefore, what your blood type (A, B, O, or AB) is depends on your parents’ blood types.

To find out what your blood type is, you will have to take a blood test. In Japan, most people know their blood type from birth. But for people who don’t know theirs, this can be easily done at a clinic. From a medical point of view, it is important to know what your blood type is for the following reasons:

  • Blood Transfusions
    Mismatch of blood type can be fatal. Prevent any risks by having your blood tested beforehand.

  • Pregnancy Risks
    Many people don’t know this but Rh-incompatibility issues may arise when the mother and fetus’s Rh-factor is different. 

  • Blood Donation
    There is always a demand for blood, and donating blood actually gives you health benefits. Generally, a prerequisite to donating blood is knowledge of your own blood type.

※ NHS, “Blood Groups

How Did the Japanese Belief Start

The blood type personality belief in Japan started when a professor named Takeji Furukawa published a paper, “The Study of Temperament through Blood Type” in 1927. Not only did Furukawa Takeji lack the educational qualifications, his paper also had no scientific evidence to support his theory. Even so, the public embraced this idea and started believing that their blood type in some way determined their personality. In fact, it inspired research into eugenics.

When Furukawa passed away in 1940, interest in blood type personality went with him. That is, until 30 years later when journalist Masahiko Nomi published “Understanding Affinity by Blood Type,” his first book about it. Before his death in 1981, he had published 6 more books in the field of which several have been bestsellers in Japan. His son, Toshitaka Nomi continued his work and even set up an organization, the Human Science ABO Center.  Both father and son’s work have contributed to the growth of blood type personality theory in Japan.

※ PRATIBHA: International Journal of Science, Spirituality, Business and Technology (IJSSBT), "An empirical study on Blood Types and Personality," p.32
※ BBC News, "Japan and blood types: Does it determine personality?"

Japanese Blood Type Personalities

What does your blood type say about you?

Similar to the Western horoscopes, the Japanese have a stereotypical belief that a person’s blood type determines or influences their personality. Therefore, insight into a person’s character can be gained from knowing their blood type, or in an opposite manner it is possible to deduce someone’s blood type based on their personalities and actions. So don't be too surprised if people ask you your blood type in Japan, or if they react based on your answer!

Here are the common beliefs that Japanese have about each blood types:

Type A

Blood Type A people are said to be:

  • The most artistic and creative of the other blood groups

  • Ambitious

  • Non-confrontational

  • Shy, sometimes withdrawn

  • Polite but distant

  • Perfectionists

  • Responsible and organized 

  • Sensitive, can be easily stressed

Type B

Blood Type B people are said to be:

  • The most practical of the other blood groups

  • Dedicated

  • Focused 

  • Independent and individualistic, can be uncooperative 

  • In tune with own thoughts, mistaken for cold and serious

  • Passionate, sometimes stubborn 

  • Relaxed or freewheeling, dislike being controlled

Type O

Blood Type O people are said to be:

  • The most flexible of the blood types

  • Confident, can be arrogant

  • Energetic and outgoing

  • Enjoys attention

  • Honest and unafraid to speak out

  • Passionate

  • Sociable

  • Strong leader

Type AB

Blood Type AB people are said to be:

  • The most interesting or complicated of the other groups

  • A combination of A and B Personalities, switchable 

  • Adaptable

  • Eccentric and curious

  • Intelligent, but whimsical personalities

  • Shy, yet is able to be outgoing

  • Trustworthy and responsible, but can be easily stressed


Blood type A is the most common in Japan, while blood type AB is the rarest.

※ PRATIBHA: International Journal of Science, Spirituality, Business and Technology (IJSSBT), "An empirical study on Blood Types and Personality," p.32, 33
※ Walden University, "What Your Blood Type Says About You: A Fun, Educational Look at Your Health and Personality"

What does your blood type say about relationship compatibility?

Since personality can be determined by blood type, naturally the idea arose that relationship compatibility can be predicted from blood type too. 

The best compatibility according to blood type are as follows:

  • A with O or a fellow A

  • B with AB or O

  • O with A or B

  • AB with B or AB

Whereas, the worst compatibility are said to be:

  • A with B

  • AB with O

Don’t know if you believe this? Well it’s believed enough in Japan that data is kept about it. According to Tokyo marriage counseling agency Celebrity, the top 4 most married couples by blood type are: 

  • O-Male and A-Female

  • A-Male and A-Female

  • O-Male and B-Female

  • O-Male and O-Female

※ Celebrity, "Marriage Rate & Combination Ranking"

So not that you should necessarily always decide on your significant other by their blood type but it might be a fun conversation to have! 

Blood Type and Life Choices

Did you know that “Blood Type Diet” is a thing? 

As its name implies, the blood type diet revolves around the theory that people from each blood type should follow a specific diet to be healthy. It is considered a fad diet made popular in the mid 1990s by Peter J.D’Adamo, a naturopathic physician. 

Is it true?  

Despite much research made to confirm the theory, to date there is no scientific evidence that the blood type diet works. Although there has been an improvement in the health of those on the diet, this was an overall improvement of their dietary habits not related to the blood type diet. 

※ Healthline, “The Blood Type Diet: An Evidence-Based Review”
​​​​​​​※ Nourish by WebMD, “The Blood Type Diet

Blood Type Diet

In Japan, the blood type diet was made popular by Erica Angyal who published books on the topic. According to her personal webpage, Angyal has been the official nutrition consultant for Miss Universe Japan from 2004 to 2012 alongside her other achievements. According to her, the recommended diet for each blood type is as follows:

Type A

Due to their supposed ancestry from agrarian tribes whose diet contains mostly plants, Type A diet should consist mostly of carbohydrates, vegetables, and fruits. Lean proteins like fish, lentils, tofu, and etc. are recommended over hard to digest red meats. Dairy products should also be avoided, take soy products or yoghurt instead.

Type B

Type B’s ancestors are nomadic in nature. Their travels through harsh environments have trained them to easily digest all manner of foods. Therefore, type B people should have a balanced diet of various foods and a little more protein to prevent lethargy and irritability. For improved metabolism, lean meat is recommended. Avoid chicken and wheat products that will increase obesity.

Type AB

Since type AB is a mashup of A and B, their digestive systems are also said to be a mix of both. A combined diet is recommended with lots of protein from non-meat sources, like tofu, soybeans, fish, lean meats, nuts, etc. Same as type B, avoid poultry and wheat to remain fit. Dairy products are also a no-no, go with yoghurt and soy products like type A.

Type O

Originated from hunters and gathering tribes, type O people need lots of protein in their diet. They digest meat easily compared to the other blood types so feel free to chomp on low fat steaks. Food high in omega-3 fatty acid is also recommended like salmon, tuna, anchovy, and more. Avoid carbohydrates that will bring your weight up, but don’t skimp on the fruits and vegetables.

Blood Type Exercise

Erica Angyal also introduced recommended exercises for each blood type. According to her, the best workout by blood type are:

Type A

Easily stressed A-people should do workouts that calm them down, like yoga that focuses on mind and body meditation. Other exercises include pilates and tai chi. 

Type B

With nomadic ancestry in their blood and a high disposition for stress, B-people need low impact cardio exercises. Try tennis, golf, cycling, light jogging, or even just long walks. For a stressed B, do yoga.  

Type AB

Same as their diet, AB-people require a mashup of A and B’s exercise regimes. Do both low impact cardio exercises and mind calming workouts. 

Type O

O-people require the most exercise, usually intensive in nature. With hunter’s blood running in their veins, do exercise that gets your blood pumping. Recommended are running, fast-paced jogging, and boxing.

※ Japan Today, "The importance of blood type in Japanese culture"

Blood Type Personalities in Japanese Media

The blood type personality theory is so widely popular in Japan that it is featured in many forms of media including drama, anime, and games. Unlike other countries, Japanese artists and game characters almost always have their blood type listed in their profile. Here are some interesting Japanese media that are about blood type personality:


This anime with 4 seasons is an adaptation of the popular webtoon in Korea called “A Simple Thinking about Blood Types” by RealCrazyMan. This anime features blood types as anthropomorphic characters in stereotypical situations based on the blood type personality theory of its own voice actors. It is a great fun way to learn about the blood type personality theory.

※ MyAnimeList, “Ketsuekigata-kun!

Blood Type Manual Series

The blood type manual series (血液型説明書シリーズ) by Jamais Jamais has 8 books - each blood type is covered by 2 books. The books are titled [Blood Type] Personal Manual (〇型自分の説明書). The books are bestsellers in Japan. 

※ Amazon.jp, “血液型説明書シリーズ (全8巻)

Ouran High School Host Club

One of the most popular Shoujo manga of all time, blood type stereotypes are mentioned several times in the manga and the anime adaptation for comedic relief. A funny scene is when two characters famous for being eccentric and scary for their sudden personality switches were discovered to be AB blood types. The main cast all nodded with an understanding look, accepting that it could not be helped. Another stereotype depicted in Episode 17 of the anime was that AB Blood Types had low blood pressure and thus were a nightmare to wake up.

※ MyAnimeList, “Ouran Koukou Host Club

Tokyo BTH ~ Tokyo Blood Type House ~

This is an Amazon Prime Video exclusive that aired in 2018 about three guys living together. It is a comedy show about friendship and features the popular blood type theory in Japan.


Japanese Media - Characters Blood Type

As previously mentioned, Japanese media are fond of including blood type in character’s profiles. This helps the audience feel closer to the characters. Here are some famous Japanese media and characters:

From Anime

Blood Type A

  • Yu-Gi-Oh! - Kaiba Seto, Yami Yugi

  • Sailor Moon - Sailor Pluto, Sailor Mercury

  • Katekyo Hitman Reborn! - Sawada Tsunayoshi, Lambo

Blood Type B:

  • JoJo’s Bizarre Adventure - Joseph Joestar, Kujo Jotaro

  • Naruto Shippuden - Namikaze Minato, Killer Bee

  • Nisekoi - Kirisaki Chitoge

Blood Type O:

  • Oregairu - Yuigahama Yui

  • Naruto Shippuden - Uchiha Itachi, Deidara

  • Cardcaptor Sakura - Li Syaoran, Kinomoto Touya 

Blood Type AB

  • Kaguya-sama: Love is War - Hayasaka Ai

  • Rurouni Kenshin - Himura Kenshin

  • Naruto - Uchiha Sasuke

From Games

Blood Type A

  • Ace Attorney - Phoenix Wright, Miles Edgeworth

Blood Type B:

  • Final Fantasy - Tifa Lockhart, Vaan 

Blood Type O:

  • Pokemon - Giovanni

Blood Type AB

  • Final Fantasy - Cloud Strife, Lightning


Blood type personalities are fun and interesting to learn about but take it with a grain of salt, it’s hard to believe that with so many people in the world our personalities can be divided into 4 small categories. Still, it is a good way to learn about Japan and now you’ll understand why your Japanese friends are asking for your blood type!

You don't have to worry alone anymore A Q&A community about Japan

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