If you want to know your actual blood type, your best bet is to go to the doctor and get a test done. This might be necessary if you decide to put up a dating profile in Japan, because over there, "personality traits linked to blood types" is culturally analogous to our western zodiac. Some people put a lot of stock into it, like the zodiac, while others do not.
In medicine, there are a total of eight human blood types: A+, O+, B+, AB+, A-, O-, B-, and AB-. These blood types are medically important because certain blood types can donate to other certain blood types and vice versa. Type O- can donate blood to anyone, and type AB+ can receive blood from anyone. In the belief that blood types hold the DNA of our personalities, the number of blood types with acknowledged differences are A, O, B, and AB, so if you know you're one or the other, but you can't remember if you are negative or positive, then you can at least proffer your blood type on a date, as strange as that may sound.
We plan to test your personality and reverse engineer your blood type according to this manner of personality categorization. Will it match your actual blood type? Will it prompt you to get out and have your blood tested by a doctor to see how close we got? No one knows until you take this quiz!