well hello there..... ricky?
Welcome to AO... Read the rules, (No dooubt everyone will tell you this) it's very important, and should be the first thing done before posting. Yep just look for the yellow Rules/FAQ link in the upper right.
And uh... If you want some feedback about your manga idea.... this is a good site to share it! Full of creative minds. I for one would be interested... so just PM me with your story line, maybe some Character info.. I will give as much honest and helpful feedback as I can conjure up, Deal?