I do not think it is both Hiro and Kirigiri, if only because they would take care to associate less during trials. I believe that the Sirens would avoid being seen as close to one another—at least, they would not publicly make plans to consult with one another, as Kirigiri and Hiro have done.

... If it is not Akira, then I suspect Raven. [Though he hates using that word because Raven is his friend, and he'd... like to believe that regardless of how this game turns out, that remains true.] But like with Akira, that is based more on following how the Chiefs might think than actual evidence.

[He sighs.]

So no. Which is no surprise, I suppose.