Well then. This isn't breaking my rule of "no yanderes" becuz the reader is the yandere not the girl, I know how to write for a reader who's insane not the love interest. Now I'm using someone different from Hazama.

Here we go.

Today was a wonderful day in King's Row, and you were looking at a picture of your obsessio- I mean crush Lena Oxton. You loved her more than anyone else could and were determined to make her yours. But whenever you tried to talk to her you were either stopped, interrupted, or she would run away. This progressively drove you more and more insane. And here we are now with you scheming to kill anyone that gets in your way. You had two real obstacles to get rid of, Talon agents Reaper and Widowmaker. Thankfully, one of them had a reason to hunt you for the price on your head. Then you saw a sniper's dot next to your head which moved to your forehead. A shot rang out which was followed by the sound of shattering glass.

(Y/N): You didn't think that I'd be ready for you?

(Y/N): Ah. That felt rather good.

You went home to wash the blood off your hands and change your clothes. Then you dragged Widowmaker's corpse and took a hacksaw to it. Then you had to make a call to a friend. It went something like this.

https://youtu.be/4kqbKEqzsAI

You sighed and took the one arm you kept and mailed it to Reaper and wrote a note with it. 

"If you want me then come and get me bitch."

You put a stamp on the package and mailed it. Almost immediately you were met with a response. Shortly after you threw sand into Reaper's face and grabbed it.

(Y/N): Now to ask her out on a date.

You took a nice leisurely walk through King's Row, and after an hour you finally found her.

(Y/N): Hello Lena. I wanted to ask you something.

Tracer: Y-y-yes (Y/N)?

(Y/N): Would you like to go out for dinner and a movie?

Tracer: O-okay.

She blushed and you led her to (favorite restaurant) and afterwards took her to see (Favorite horror movie). During the movie she kept a tight grip on you that only got tighter with every jumpscare. After the movie you saw Lucio peeking from the alley behind the movie theater. You looked at him, put an arm around Lena, and pulled out Reaper's mask after that he was scared shitless.

(Y/N): Do you want me to take you home?

Tracer: I wouldn't m-mind coming home with you.

It was cute how she stuttered when you were around. You planted a kiss on her forehead and the two of you went back to your home. Unfortunately you forgot to feed one of Widowmaker's legs to the lion and Lena saw it.

(Y/N): This is quite unfortunate. You weren't supposed to see this. So now I guess I can't let you leave. Time for you to go to sleep.

You stabbed a syringe into her neck and picked her up after she passed out. You carried her to a chair and tied her into it.

Several weeks of learning hypnosis and using said knowledge of hypnosis later.

You were looking out on the balcony of your home admiring the view.

Tracer: (Y/N)? Is something wrong?

You looked over your shoulder.

(Y/N): What makes you ask?

Tracer: You usually only come out here when you're upset.

(Y/N): Oh that. No I'm just looking at the sunset. No matter where you live it always looks good.

She walked over to you and leaned over the railing.

Tracer: You got that right love.

~End~

Well then. There's the first yandere reader story. Probably the last too. I'll see you all in the next chapter.