[She'd know, because she herself had to ask after Toshi had tried to explain stuff to her.]

You and me both, mister. It wasn't until I was brought here and saw with my own two eyes what was going on that I had to believe it wasn't just a legend, but the truth.

I'm still a little unclear, but apparently it's through some sort of magic that pulls people from different points in time and bringing them to this world to fight against Orochi.

Or more clearly, Orochi wanted to bring people from all time periods and fight them all at once.

[Again, as Toshi had tried to explain to her. That, and talk of having to fight off demons.]

Does that help you some?