Game of the Insane (Yandere Haikyuu!! x F!Reader Oneshots)

RIVAL (Kageyama Tobio and Nanase Haruka)

Title: Rival

Pairings: Kageyama Tobio x Reader, Nanase Haruka x Reader

WARNINGS: yandere themes

Rival

/noun/

one of two or more striving to reach or obtain something that only one can possess

Kageyama thought he had taken care of your problem.

You had a certain habit of picking the same sort of guys- tall, dark-haired, handsome, and rarely showing emotion. Kageyama fit all of that to a T, yet you had the nerve to turn him down.

It had all come to a head when your latest boyfriend noticed Kageyama following you both home. He and Kageyama got into a fist fight- one that your boyfriend most definitely did not win.

You had given up on dating completely for about a year now.

So what were you doing with him? That emotionally-constipated swimmer boy?

Nanase Haruka was a perfect example of your type. He swam through life with an aloof, detached expression. Where Kageyama was the star setter of the volleyball team, Haru was the star freestyle swimmer on the swim team.

Haru's calm, collected personality had drawn you in, maybe because he was such a stark contrast to Kageyama's fiery possessiveness. Where Kageyama was fire, Haru was water and, most unfortunately, water almost always won against fire.

Kageyama had watched the two of you meet at the university pool. At first, he had been caught up in admiring your swimsuit-clad form. Then, he realized that you were talking with someone who fit your type a little too well.

Kageyama knew everything about you, so he was not surprised when you announced to the world that you were dating Haru, with a social media post of you slinging your arms around his neck. He was angry, yes- furious even, but not surprised.

He began to see Haru turning possessive, not allowing you to speak to others without him next to you. He watched as you lost friends, but put it all aside because your rose-tinted goggles favored the swimmer.

"You think you're better for her?" Kageyama glared at Haru, the two men alone in the locker room together. Haru used his towel to wipe the pool water from his face uninterestedly, and Kageyama's hands balled into fists.

"She's happier with me," Haru said with an infuriating smile, "And she should be with who she's happiest with."

"That should be me," Kageyama snarled, stepping closer and cracking his knuckles, ready for a fight.

"Then maybe you should ask yourself why it isn't," Haru said coolly.

His words hit harder than any physical blow could and Kageyama's heart twisted with envy. He watched as Haru walked out of the locker room, a smug grin on his face, with a mixture of rage and fear.

Fear, because deep down, he knew Haru was right.

—---------------------

Was Haru really any better than Kageyama was? You were beginning to wonder if that was really the case.

The dark-haired swimmer had an arm thrown around your shoulders- yet another sign of his possessive behavior. He remained silent as his friends chatted around the lunch table, but the unsaid threat was there.

Don't say a word.

Thankfully, his friends seemed to understand Haru's behavior because never once did they direct any of their conversation to you. Sadly, you gazed across the cafeteria at your old group of friends.

Too bad Haru would never let you talk to them again.

Haru turned to you and whispered into your ear, "Why not drop out and move in with me?"

You stood up suddenly, halfway falling off the bench. Nononono. No way in hell were you going to do that.

The way Haru glared at your reaction was the breaking point. You were not going to let you manipulate you into dropping out of college. And you were not going to let him take away your freedoms any longer.

"We're done," you said, "I can't take this anymore."

Haru's eyes widened, "You don't have to move in."

"It's not just that it's- you're too possessive. I want to have friends, Haruka."

Haru gritted his teeth, "Then you can have a friend or two-"

"No! Not just a 'friend or two'. I'm sick of you controlling me! We. Are. Over," you stormed away, furious with him and with yourself for letting him control you for so long.

You approached your friends' table and, after explaining to them that you and Haru were no longer an item, they welcomed you with open arms. You had forgotten what it was like to have friends and were completely blown away by how much fun you were having talking to them again.

At his friends' table, Haru was seething.

—--------------------------------------

"What happened to 'she should be with whoever makes her happiest'?" Kageyama mocked.

Haru gritted his teeth, "If you don't want to then-"

"Who said I didn't want to?" Kageyama snapped.

The two men looked across the park, where you sat under the shade of an oak tree, laughing alongside a tall, dark-haired man- one that was neither Haru nor Kageyama.

"It's a deal then?" Haru asked.

"Yes," Kageyama replied, "We kill him tonight."