Yaku is a detective and you're a badass killer
Requested by @PurrfectLibero
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"How many bodies do we have this time?"

"Two downstairs and three upstairs."

"Shit."

Yaku tapped his chin with a pen he was holding as Lev lifted up caution tape for him to walk under so he could enter the crime scene. As he did, he could've sworn he heard a snicker behind him, causing him to turn around and face Lev. He was obviously trying to contain himself.

"What's so damn funny? People are literally dead inside this house," Yaku questioned, his brown eyes nearly glowing with anger.

"I was just thinking about how I didn't have to lift the tape up very high for it to be over your head."

Yaku closed his eyes for a moment and tapped his shoe against the ground of the front porch as he tried his best to resist the urge to kick his subordinate's ass. "Officer Haiba, would you like to do your job now or continue to insult your superior about his height and get your ass beat?"

Lev's face quickly paled and he gave Yaku a bow of courtesy before shuffling into the house. Satisfied, Yaku entered the house, glancing around at pictures on the walls, at shoes on the floor, and finally at the two bodies the photographers were snapping pictures of.

The coroner nearby approached Yaku, recognizing him as the lead detective on the case, and listed off the causes of death to him as she showed him the bodies. "Strangulation, blunt force trauma, two slit throats, and a stab to the neck. Time of death: less than two hours ago. The crime was called in by a friend who visited the house and noticed that the residents were dead when he looked through the window," she explained.

Yaku sighed as he looked around the room where he and the coroner were standing. Who could've done such a thing?

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Sighing, you removed your shirt and pants from the drying machine. Upon checking your clothes for any signs of blood and finding none, you carried them up to your bedroom and hung them up in your closet. Once you were finished, you made some popcorn and sat down on your couch to prepare yourself for a Netflix marathon all night.

While most people went out on Friday nights and had fun at bars, you preferred to kill those who had wronged your family before settling down with a nice bowl of popcorn and pretending none of it had happened.

They had deserved it and you knew you wouldn't get caught. You'd been reading up on police investigations into the murders you'd committed and the only thing that popped into your mind was how hot the leading detective was. And if that didn't show your lack of worry, then there wasn't much else that could.

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"Detective Yaku!" Lev cried as he ran into his superior's office the next morning with a stack of papers, "Look at what I found out!"

Yaku flinched slightly at the sound of hearing Lev's loud and enthusiastic voice so early in the morning. "What is it?" he wondered as Lev slapped the papers on his desk and sat down in front of him.

"I did some digging last night and found that the friend who reported the murder—"

"The one with all the piercings... Terushima Yuuji?"

"Yes! He was a member of a local gang and so were those men who were killed at the house yesterday. In fact, each murder that we've investigated in this case has involved a gang member from this one gang being killed," Lev explained.

This information piqued Yaku's interest, causing him to sit up straighter in his chair so that he could reach his computer and enter the police department's database.

"What about those murder weapons?" Yaku questioned.

"The same deal: each weapon belonged to the house's owners and, therefore, was left in the house with no trace of fingerprints other than those of the owners."

"Damn it..." the detective murmured under his breath as he scrolled through the database to find other crime cases linked with the gang Lev mentioned.

He had an idea.

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Later that same day, you shoved your (h/c) locks into a hair net before covering it with a (different h/c) wig. You then pressed down the edges of your mask once more and looked at who you'd transformed yourself into in the mirror—the courier identity you'd formed to meet up with the leader of the gang yesterday before you'd killed all those gang members.

With each set of murders you committed came a new courier and thus a new identity.

Once you'd put the finishing touches on your face and outfit, you grabbed a backpack and searched through its contents. Upon noticing that the bag of crystal meth you'd been saving wasn't in there, you frowned and proceeded to root through different parts of the backpack before checking your entire apartment.

"I probably left it in the car..." you muttered, picking up the keys off the coffee table before slinging the backpack over your shoulder and heading down to the garage underneath your apartment complex.

Just as you were about to unlock your car, you noticed someone standing behind it, resting their weight on the trunk. "Oh, hello there, (l/n) (f/n)," Yaku spoke calmly and with a knowing smile on his face, "Nice methamphetamine you've got here."

He held up the bag you'd been searching for, making you laugh spitefully.

"So you really are as smart as you are handsome," you commented as you took off your wig and mask, tossing them on the ground as you approached him.

He didn't reach for his gun or even flinch in the slightest as he responded, "I hope that's very." The only thing throwing him off at the moment was how beautiful you were without your disguise.

You nodded and smiled. "It's a good thing you found me. I was just on my way to kill the big man and all his little goons."

Yaku shrugged and returned your smile. "I figured. You're one smart woman, but I'm sure you know that already?"

"Nobody's ever really told me that before, Detective, so thank you. How'd your investigation go?"

Yaku looked into your captivating (e/c) eyes as you walked over and stood next to him and placed a hand on your hip. Knowing he had your full attention, he proceeded to explain to you how he'd figured out you were the culprit.

There had been traces of crystal meth each of the scenes of the murders and some, if not all, of the victims had been under its influence. You'd dressed yourself as a different courier on each trip to the houses. On the first trips, you'd claimed you had gang affiliations and access to the best drugs, and you'd make drug deals with the gang members. While you were in their homes or hideouts, you'd examine your surroundings and figure out your plan of action so that when you came back the second time with drugs you'd stolen from the people you'd murdered before, it would be easy for you to get the gang members high and kill them with tools in their own home.

Your motive? Members of this gang had mugged and murdered your parents in cold blood out of desperation for money and anything they could sell to get drugs. Because of this, you'd decided to return the favor and go on a killing spree and murder each gang member solely out of revenge. Your next target had been the leader, but Yaku was now going to make sure you didn't get your hands on him.

"You're a real gem, you know? Some of the people who work as detectives and cops are real dumbasses," you stated once he'd finished.

Lev immediately popped into his mind, making him roll his eyes and chuckle. "You got that one right."

You clicked your tongue as you looked around the parking garage before returning your gaze to him. "So... are you gonna arrest me, or what?"

"I want to recruit you to help me, actually," he proposed, his brown eyes bright with hope, "Nobody else will really know about it. It'll just be between you and me, but you're a smart woman, like I said before, and I could use your input to help me solve some cases."

You were shocked by his offer, yet flattered. Yaku noticed your moment of pause as you contemplated his offer and extended the bag of meth towards you as well as your wig and mask that he'd picked up off the ground.

"Destroy these as well as any other evidence and stay with me, or I'll take these to the station along with you in handcuffs."

You smirked and accepted the items he gave you. "As much as I like the idea of being in handcuffs when you're around, I'd prefer to stay out of them in this situation, so thank you, Detective."

He couldn't help but chuckle at your dirty comment before smiling at you and saying, "Please, call me Morisuke."