I agree with anon on those things, but it was a otherwise good story. this leaves me wanting more, and that's what a good story does. Keep writing!

1. "It was a normal Friday afternoon, around 4 o'clock. Or so I thought." This sentence is worded rather awkwardly. At first I thought that she was wrong about it being 4 o'clock, instead of being wrong about it being a normal Friday.

2. I didn't really understand how your main character felt. I understand that she owes him for saving her life, but how did she feel after he saved her from drowning or when he stopped his girlfriend from killing her? How did this lead to her feeling as if she owes him? (And how did she kiss him, even though he had a girlfriend? And why did he protect her? I think there's probably a really interesting story behind that. :D Was he comforting her, were they realizing that they had a connection, what was happening?) I think that if I knew what she was feeling then I could sympathize with her.

All this aside, I really like the idea of your story. :)