I was always intrigued by a Yandere Simulator Mission Mode story and this universe, different from the canon one. I wondered what it would be like to be a young assassin like Yan-chan, creeping through halls, waiting for the chance to strike.
So, here we go!

Warning: contains extreme bullying and mentions of murder.

Mei raced down the hall. Her heart was beating right out of its chest. She wanted to get far away as possible, but endurance had never been her strongest point and she was running out of breath very quickly.
Keep going, she thought to herself. Maybe you can lose her if you go down that way-

WHAM!
Musume pounced on Mei and knocked the other girl to the floor. Placing one hand on Mei's chest, she pulled a pair of scissors from her pocket with the other hand.
Mei shivered as the blades approached her body. Being chased out of the locker room in nothing but a bathing suit was already bad enough. But not this! What had she done to deserve it?

"Let go of me! I have done nothing to you!" the blue-haired girl spat. But Musume didn't even blink.
"If you don't shut up in five seconds, I'm gonna cut away all this fabric so everyone can see those hideous things you refer to as breasts!" Musume chuckled. Mei stopped struggling and tears blurred her vision as Musume snipped away at the edge of her bathing suit.

The scissors cut away at the fabric surrounding Mei's left leg and made their way upwards. The blades felt cold and evil and they tore through even more of Mei's swimsuit, leaving her skin exposed. Musume reached her scissors towards Mei's neck, but she slapped them out of her hands.
"What was that for, you little prick!?" Musume yelled. She slapped Mei hard against her cheek, then stood up to fetch the scissors. Mei took this time to stand up and run back to the locker room, sobbing as she went.

When she finally got back to the locker room, Mei was glad to see that it was empty; everyone was out swimming laps. But sadly for her, her clothes lay in a messy and torn pile at the foot of her locker. Clearly Musume had gotten to them before Mei did.
Mei grabbed a towel and covered herself up with it, dropping her head into her hands. The tears washed over her and she began to wail and sob.

What made Musume want to bully her? Why did she do the things she did? How was Mei gonna get to class now? She still had one more period before the day was over and didn't want to spend it in a torn-up bathing suit.
The sounds of students chattering grew louder as Mei's classmates headed into the locker room, all of them dripping wet. They began to trip off their wet swimsuits and step into clean clothes. Mei watched them enviously.

"Mei! Where have you been? What happened to your swimsuit? Where are your clothes? Wait, are you crying? Or, were you? Can you tell me what's wrong?"
Saki, one of the girls that Mei hung out with after school, sat down beside her. "Come on, tell me."

Mei wiped away some leftover tears. "It was...it was...it was Musume. She...bullies me...does it everyday...look what she did to my clothes! I can't go to class in this!" she sobbed violently, recoiling when Saki tried to gently touch her shoulder.
"Don't worry, you'll get to the bottom of this. In the meantime, you can borrow my gym clothes. That way, you'll have something to wear. Though you might need a new uniform-"

"You think!?" Mei asked sarcastically, holding up several shredded pieces of her skirt.
Saki rolled her eyes and passed Mei the clothes. She wasted no time changing into them and followed the girls back into the school building. As she headed down the hallway, Mei could see out of the corner of her eye Musume. Watching her, smiling.

It wasn't over yet.

Mei didn't want to do this...but she didn't see any other options.

While bullying was discouraged at Akademi High, the teachers couldn't do anything about solid proof. Mei had tried to collect her cut-up clothes, only to find that they had been taken. Her guess was that Musume had stuck them in the school incinerator.
It was high unlikely that Musume would care about the punishment she'd receive for her treatment of Mei. The girl was the daughter of a wealthy company owner and would most likely inherit it. School didn't matter the least bit to Musume, who already had a career as the future head of Ronhsaku Loans under her belt.

Mei knew any plead or attempt to get Musume to stop would be pointless. So, in the safety of the Cooking Club, she let her finger hover over the mysterious number. Finally, she took a deep breath and pressed it.

"Hello?" a feminine voice asked. Mei hesitated. Did she really want to do this?
"I suggest you respond, Mio. I don't have all day...well I do, since you're the first person to use this number...just, tell me what you want."
"I...I want Musume Ronshaku gone."

Silence. Then, the voice. "I wasn't surprised. I've seen what she's done to you. I didn't expect you to call this late. But...how do you want her gone?"
"I-i have a choice? I j-just thought y-you could arrange something, like an accident-"
"Everything in my office is done on purpose. Now, how do you want her gone?"

Mei gave the question some thought. Revenge was in her hands. She could arrange for anything to happen to Musume. Anything...
"She cut up my swimsuit today. I want her to be eliminated in her swimsuit. Don't care how, don't care when."

"What an interesting offer. I'll see that it gets completed as soon as possible. Thank you, Mio; we'll talk again when the deed is done."
With that ringing in her ears, Mei hung up. Revenge was about to be slivered.

So...this is how Mission Mode will work: one chapter that talks about why the client wants a certain person gone, one chapter about Yandere-chan getting rid of said person, and one chapter of the aftermath. Maybe some other stuff too, like the introduction of a certain character...

I will take requests too! If you want, you can send me the client, who they want gone, why they want that person gone, and how they want them gone. I will do in-game characters, rivals, and maybe Ocs. We'll see about that last one.