I have been playing this game since...I can't remember. And I wish to know who the mystery girl is, the one between Irinlia and Sara in the CG room. It says that she can be encountered during the main story, but the thing is, I've finished all current main story lines, and I am confused. But back to the main question. How do I get her?

I think you mean Lace. You get her during the main story line.

Huh? Oh wait...ohhh, I am so stupid. I reset Lace to take a look at her in the good path. I think it resetted all my progress with her. Thank for replying!