[... geez, if Blake thinks Jin's a "skinny little twerp", Yusuke doesn't even wanna know what he thinks of him. It's probably better not to ask. So he doesn't! Instead, he responds to Blake's appraisal of Jin's physical appearance with a little "tch" and says:]

Doesn't matter. He's not human, so if this'd been home, that Aerodactyl woulda been caught in ten seconds flat. Trust me, I've fought him before, so I know what he's capable of.

[Yusuke's not unaware of the fact that he's never properly broached the topic of demons and world-saving and shit with Blake, but that doesn't really stop him from (sort of) doing so now. He might be comfortable with keeping his Spirit Detective stuff to himself unless somehow prompted to do otherwise, but he's not nearly as comfortable with the idea of lying about or covering up who - or what - Jin is, especially when Jin himself is pretty forthcoming with that information. Call it a weird expression of loyalty to his buddy if you want, but either way, bam. It's out there. Blake is free to make of it what he will.

As for where he's from...]

Japan. Y'know, that country out in the ocean? The one that's a little farther to the right on the map than China is? That's where I'm from. Better keep it straight from now on, old man.

[Or else he'll bite your head off again. >:E]