Is it Possible to Unlock Rachel as a Playable Character?

Rachel has three chapters to herself and then there are a few missions which you play as her.

Maybe in NG2 they will expand the playable character roster (we might get to play as one of the DoA ninjas? >.>).  Check out this video of Rachel's gameplay in action:

But they really should have at least made Ayane a playable character or something. She could basically control exactly like Ryu and have maybe one or two unique weapons. Maybe her throwing knives did something with the little pinwheels.

I would think it would be a lot easier to program a new playable character than to design entire new levels for a different character that can only be used during those sequences. Personally I think being able to use a different character through the whole game adds more replay value than a new chapter. But that's just me.

Well, she just goes through the same areas that Ryu goes through and her chapters are kind of short if you're speeding right through them. In my opinion she is pretty fun to use, and I do agree I would rather have been able to play as Ayane, gathering information for Ryu and seeing what was going on behind the scenes. But then again I don't think Team Ninja would want to make a game that was really heavy on story.