Somehow I like it, yet somehow I don't. Your outlines aren't that bad, though some need to get fixed, but you haven't paid any attention as to perspective, composition nor the difference in proportion between male and female. + There's no screentone
The story is funny, but I feel like you're rushing through it, which really isn't necessary, with all the actions in it, it won't get boring if added one or two pages extra to just show some more regular events that happen before the main activity starts. (It's a bit hard to explain, but I try to tell you to put in some 'break pages' in between two different activities. Like when Koari got chosen for the Cosplay event, explain what she has to do and what she thinks of it while laying in bed for example. Just cut a break, don't go directly to the catwalk.)
About the proportion, I noticed that some guys have really thin necks, which is totally not guyish at all, guys have thicker necks than girls, so take a notice.
You can also study the differences between male and female characters on websites or in books.
Well, I'll have to go now, it's dinner time here
Good luck with your manga and don't forget to visit mine:http://animaltamer.smackjeeves.com/