"Toushirou." And that's all Blaise is getting for introductions. He isn't entirely rude, and all.

It's . . . also about all he's going to get, period. Toushirou is definitely not encouraging this. "No. I have other things to do."

This is actually decently polite of him; he could have flat-out told Blaise that he finds him extremely annoying. Which he has done to many people on many occasions. He seems to have a habit of running into irritating people. (Perish the thought that he's just too easily irritated. That's silly.)