Board Thread:Episode Discussions/@comment-25319479-20170614103743/@comment-24142271-20170616090910

The Wikia Editor wrote: I've heard a surprisingly compelling theory that the masked person is Sumire. I didn't even think about it while watching the episode, but people have pointed out a couple of possible hints.

The glance she got from Mitsuki in Episode 8 after she asked Boruto if something was wrong, the fact that she is Class Rep and yet we still don't know any of her abilities. Also, she is an orphan according to the novel.

Some have even suggested the idea that Sumire's personality is just a front, like Tobi was for Obito. Although, I'm not entirely convinced.

If true, it certainly would be a clever misdirection. Why must every single character that wears a mask or we know nothing about have to be someone we know?