There is an idea that I would really, really like to do. This can be yaoi or yuri. I sort of prefer the idea of it being yuri, but if it is yaoi, I am more likely to stick with it for longer. It is up to you.
The story revolves around a teacher student relationship. Normally, I epically and dramatically cringe at this, but this time, I am going to spite myself.
My character is in your character's homeroom. The way things work at the school, they have the same home room for all four years of high school, but they don't have their homeroom teacher for any actual classes. Well, in the second year, the teacher, your character, steps forward to stop bullies from harassing him/her. My character has been bullied since getting into school and has never once had anyone help him/her out. Well, they develop a close bond over the last few months of school, and the year following, my character ends up falling for yours, but doesn't admit it. Finally, my character is faced with their senior year. Over summer, they go through a rapid transformation, trying to become "desirable." Upon returning to school, they start to actively pursue your character. Your character at first resists, though they do have feelings for mine. Right before winter break, my character pushes the issue and molests your character. We can decide where things go from there (your character tries to avoid mine, your character invites mine to stay over for the break, etc). Before valentines day, they end up in a romantic relationship. Mid-April, they get caught by one of the bullies and the bully uses it to blackmail them.
I have an idea for this part in the plot, but this would add a second story or a love triangle to the plot. If you are interested, ask.
Of course, if that doesn't interest you, the bully goes back to being an ass to my character and forces your character give them good grades, exploits them for money, and so on until the school year ends. Then, they return the evidence and act like it was all a joke.
If we get that far, I'm sure we'll have come up with more ideas to keep it going.