I wanna write something really yandere...and....oddly...I don't want to write the fucked up character. O_______________o
I'm serious!
I want to write something that starts out with a normal relationship. Your character has always admired mine, and finally he works up the courage to ask him out. My character is your typical smart, sporty teenager that everyone adores. He is a closet case (and most people refuse to even consider that he is gay). Yours needs to be either slightly less popular or one of the "bad" groups (badboy/goth/geek/nerd/etc). Mine doesn't know much about yours, but he agrees, thinking that yours is cute. For a short while, they date in secret, mine noticing that yours is a bit clingy, but not thinking much about it. Their dates are always at one of their houses or in a different town completely, never where anyone could see them together and guess at anything.
Then, bored already, he breaks up with him through text message. Rather shallow, he doesn't feel like having anyone read the messages, so he deletes them and blocks your character's number for good measure.
That night, he is walking home from a friend's house and gets jumped. When he wakes up, he is your character's basement, tied to a chair, naked and beaten. Your character threatens him, beats him, and rapes him. When he releases him, your character tells mine that there is no escape. If anyone finds out, they will view him as weak, and everything he had just been through would be repeated over and over. Fucked in the head and fragile, my character believes.
The next morning, he wakes up in his own bed. Looking at the bruises, he is reminded it really happened, but now he is a little (though not much) more stable. Closing his eyes, he tells himself that he won't tell anyone anyway. Your character is weaker than him, and there is also a chance that your character could produce proof that they had dated. Even though it makes him feel sick and frightened, he decides to try and forget it.
As if your character knew he would think this, he opens his locker and finds it stuffed with pictures of them. Some are from while they were dating, but plenty were from the night before. Sickened, he stuffs them all into his bag. When he confronts your character, yours just smiles, kisses him gently and tells him that if anyone finds out about what is going on, everyone my character so much as talks to will get the picture mailed to them. It is quiet obvious that he is serious, so my character stays silent.
He tries to convince himself that it is the end, he'll just have to forget it all. Unfortunately, your character shows up that night again. He rapes and beats him again, this time taking pictures and threatening to send them to people if my character doesn't beg for him to fuck him. By the time it is over, my character passes out and finds it a relief.
For weeks, this continues, and your character continuously takes bigger and bigger risks, coming when my character's parents are home, hanging out with him at school, and even fucking him in the supply closet at school. One time, they are in one of the unused classrooms and your character tells mine to cry out, tells him to see what happens. As he is doing this, my character can't find his voice, and your character tells him it doesn't matter. Those people are no different from him. If they had the chance, they would do exactly what he was doing: pinning him down and fucking him like an animal. The only difference between him and the rest of those people is that my character knows what yours is after, knows all of the evil inside of him. The rest of them, they could hurt my character anyway they want to, because he lets them so close.
He is starting to believe it and starting to think that this will never end, so he tries to kill himself that night in his bathroom. Your character breaks in and saves his life. When my character comes to, he is ties up in your character's basement once again. For months, he is kept there, your character updating him on the search for him as he repeatedly rapes and abuses him.
Finally comes a day when your character is acting agitated and he nearly beats mine to death. Thinking he actually killed my character, he hangs himself in his bedroom. When the police are going through his house, my character is found.
Things can end there or you could create another character that comes into my character's life, either as a lover or as a friend, who helps him coop and mentally adjust after the ordeal.
Like I said: yandere as fuck. :3