"I'm a doctor, Kotaro. That kind of thing doesn't happen. I've never heard of that kind of thing happening in all of my research. And I'm considered an expert on vampire physiology. --Uh, on how a vampire's body works." His rhythm was broken a bit by his pause to explain a word Kotaro might not know. "My brother is a vampire, and the woman I've been seeing is a vampire. I'm not." Oh dear, here comes that headache again.

Kotaro, you might have to resort to drastic measures to get this boy to drink some blood.