Set me free....

Okay, first of all, the plot was okay. I liked the story as a story, but it wasn't very rich in detail as a story should be. Putting more details in with the dialogue helps to create a picture for the reader so they can understand exactly what's going on. For example, when Sen admitted she loved Zaku, all it says is that she's fiddling with the blanket. What's her expression like as she's doing that? Putting more action with a few actions help out a lot. You should try and put as much in as you can. ^^
 
As for grammar, utilizing spell check would benefit you as well as the reader so we can all understand what you're trying to say. It's not so bad to say that no one can tell what word you were trying to put in there, but it would be better with correct spelling.
 
Paragraphs are grouped in subjects. The dialouge is the same way. Every time a new person starts speaking, a new paragraph is started. Your paragraphs are too long in this, making it hard to read and I got lost easily. It was a little hard to follow, too.
 
I'm sorry if I seem a bit harsh, but the truth is better than lies, right? I hope I helped. I'm still pretty far away from perfection in writing (far from it) but these are things I'm trying to improve on myself. The story was pretty good, but revisions normally make it all the more interesting and exciting.^^