maybe -
How can we sure about if any of those information is correct ...or not?
Ahh sorry was my tone a bit strong? I was just a bit excited, not meaning to put anyone down. I assumed everyone already know J-pop, J-Idol, J-everything has to put out bloodtype information for (prospective) dating purpose.
When I said I don't understand Japanese obsession with bloodtype, I meant I know of the what, but can't comprehend the why.
Thanks for your link to Jp wiki on bloodtype. Not knowing Japanese myself, but it's easy to compare the Japanese, English, Chinese versions of the same topic. It's clear that only Japanese put a lot of weight into bloodtype subtypes. I happen to work in the healthcare sector so I do know about about medicine and I can tell you bloodtype is not that important in real life, it's only use in blood transfusion and organ transplant.
More relevant is this page:
血液型性格分類
Or in English:
https://en.wikipedia.org/wiki/Blood_types_in_Japanese_culture
I just want to add that these pages imply that China, Taiwan and Korea also buy into it, well I can't speak for Korea, but definitely in China and Taiwan, bloodtype-personality correlation is not taken seriously.
As for honesty in the bloodtype data... it would be interesting if correlate the stereotyping of each JAV idol with their publicized bloodtype, e.g. would idols who perform a lot of dom vids be type B, or idols who are typecast as sub or innocent as type O. Even better if a JAV idol's bloodtype changed over time (as she gets older, her career might gradually shift from sub to dom) that would be solid proof that bloodtype is mainly used for marketing purpose.
