Tidus stops at around the 'heart stuff', being trapped in a heart, a - her friend's body. Brow tugged together quizzically, brain trying to wrap itself around what Kairi's explaining. Uhhhhh.

"So your heart, you mean like- a soul." He points a forefinger from one place to another. Soul going from Point A to Point B. "Your...consciousness. And some kinda magic put you in there."

Oh, wait. "Did your friend knew you were in there?"