First and foremost, I'm trying to dig up Tenchi Masaki's blood type. 
Does anybody have this information?

Since we're on the topic of blood types, I've noticed that, typically,
Rh factor (the positive or negative in a standard blood type) isn't
listed with any anime character blood type I've seen (even considering
what few I've seen).  Is it just that the Japanese don't put much
emphasis on such a seemingly important detail?