My Family's boyfriend By: Eritay. Title 5/5: Yout title fits the kind of story you are writing, and it fits the plot very well~

Poster 55:  You did not have a poster for the story,  but you do not loose points for that~^^

Description & Foreword 10/10: Your description is well written and there are no grammar or vocabulary mistakes.
Layout 4/5: Your story is very organized and neat. But on your chapters, the way your sentences continue on, and they look like they are coming of the page, but aren't just makes it look a little confusing and kind of not neat.

Characterization 13/15: You are very deatiled with your characters! Which is a very good thing, and you should keep it up. But i think you need just a bit more details on how your chracters feel, and what they see. Pretend you are in their shoes and go from there.

Plot 28/30: Like i said above, you need to focus on more details about their surroundings and feelings. It helps inprove in your writing skills, makes the story more interesting and the chapters will be longer.
And also to answer your questing about the flow of the story, i would just keep it at the pace it's at now, since it's a good pace, it doesn't move too quickly!

Grammar and vocabulary 15/20: The only thing you had trouble with was with how to word certain sentences. Example: 
Because our last block is math, and Koharu and Eddy are in advanced, we were in different classes
Should be