I like your plot, but you talked to much about the girl being tied up. No offense, but it was almost like you wanted to be tied up YOURSELF. I've been through that phase when I was 8, don't worry. Also you sort of raced through the story. Everything happened so quickly! I was going to write a story like this and post it on here, but I thought better of it. I wonder if it would have turned out anything like that.

Overall, nice job! Hope you're not too offended. (see, I can criticize, but I don't even listen to my OWN criticism)