It is Miyako--and I didn't find this out until recently, but Miyako's face is never shown in the manga. in the anime, some fans say she looks like Orihime, but I just don't see it at all.

There was one really laughbly bad Teen!Mokuba fic I came across called "Bad Habit," and every cliche for teenagers in general and Seto/Mokuba was jammed pack in it. It turned out the author was injecting her own RL into the fic. Once she got sober, she pulled it down and wrote a better, if not entirely great, version of the story.