First and foremost, Charlie hadn't saved Tanya to do Yoshitaka a favor, so he shouldn't think too highly of himself.

Secondly, Charlie didn't care how big a deal he was in Japan.

To Charlie, he was nothing.

Yoshitaka certainly felt embarrassed as well, as he could see that Charlie thought nothing of him when he didn't even know who Charlie really was.

Until now, if anyone ever did Yoshitaka a favor, he just had to tell them he would remember it, and they would be so overjoyed as if they had