Books about blood type on sale at a 100-yen shop.
One of the more curious aspects of Japanese culture is that they've concocted a way of "predicting" personality based on blood type. They believe that certain traits come along with certain types, and that various types are better matrimonial matches than others. I have always believed that this is the consequence of having a culture where people look roughly similar to one another. Western cultures assign character traits based on hair color or other physical aspects, but the Japanese have to go further than skin deep for their superstitions and horoscope-style character theories.
I always get a kick out of discussing these theories with Japanese folks, and I'll miss hearing about them.