[Ishida remains where he stands as the biker comes closer to him. He's definitely no longer afraid of him, although with every word Mondo says, he just becomes more worried and perplexed instead. Whoever this kyoudai really is, they're truly important to him.

Thus, he can't just leave him!]

I assure you, I wouldn't joke about this! It would be a far too cruel 'prank' on my part! [Not that he likes any pranks...] But let me help you, I'm willing to search for your actual kyoudai! What does he look like?! And his name?!