My summary from Mr. Masahiko NOMI's book "Ketsueki-gata Josei Hakusho" (Blood-Type Women White Paper).
Personality differences of men and women is almost nonexistent. However, Type O people are strongly conscious of their sex. Even a boyish type-O woman thinks she is a woman after all. On the contrary, if a type-AB person seems to manly or feminine, it seldom considers sex distinction.
The strong consciousness of sex is the indication of the natural nature of Type O. However, Type O personality is *not* primitive but natural. In other words, natural means humane. As the blood type becomes type A, type B and type AB, apart from the nature a little by a little and from the human.
A type-O woman sometimes does not seem to be feminine. Natural differences of personality between men and women are small, but social differences are large.
A type-O person gives priority to its life and actions, first of all. Various personality traits of type O are born from there.
Surprisingly strong reality is of type O. O gropes the most advantageous action to exist, distinguishes pluses and minuses swiftly, is a good decision maker.
Purpose-orientation is O's nature and O considers the purpose on real life intensively. For example, a purpose to get occupations and jobs, a purpose to seek the opposite sex, especially a purpose to hold the power. A type-O person doesn't show the zeal for the target isolated from real life.
When such purpose does not exist, a type-O person gets into awfully unstable. If the situation continues so long, it becomes like a cat in a sunny place.
The romantic expression of type O and the tendency to prefer such things seems to be contradictory to reality at first glance, but in reality, it is making an effect driving realistic behavior. Type-O person has the dual personality; romantic and realistic. But this is very superficial view. A romantic thinking usually doesn't become to an action.
Shigeyuki Yamaoka (2001), A Psychology Book for not to Become a Useless Adult
Self report of personality from 1 (strongly disagree) to 5 (strongly agree); Subjects are 649 university students who love blood-typical topics.
I haven't really seen all the above characteristics. But fellow feelings, consciousness of sex distinction, generosity, reality and purpose-orientation are the vivid characteristics.