Yuya, we love you even if others don't! I can't imagine SDK working without Yuya; you've said often enough that she's the glue that binds the group together at least as much as Kyo. Kyo may be what brings the other guys in, but I think you could argue that Yuya is what keeps them there.
It's sad that shounen females don't get the love they deserve; I think so many of them rock, despite the fact (or perhaps even because of the fact) that they're constrained into certain roles by being women-in-shounen.