One of my Japanese male acquaintance once told me about the blood type was an indicator of personality. I didn't believe in that theory at all and I tried to give him a tip, " It's not scientifically proven that the blood type is an indicator of personality. You shouldn't tell other people about that because they might laugh You". But he was very upset and tried to persuade me to believe in the theory.

I had to realize that the faith is so strong for some people that you need to be careful about that.