Requested by @HideIsJustAsleep. Just a warning some grotesque imagery in the beginning if you're sensitive to that stuff.
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Ever since I can remember, I never belonged to society. I was never...normal.

You ran through the dark streets of a city in Japan, you didn't know which one and you didn't care. You just needed to get away from them.

"Oi I think it went this way!" You heard a gruff male voice exclaim, your eyes widened as you picked up your pace.

I'm not even seen as a real person even though I have a body, emotions. I'm just an entity.

You skidded to a stop at a corner to catch your breath.

"Found you." Your eyes widened as you turned your head peering into the eyes of a government agent. Although to you he didn't seem like an agent, he was more of a thug. You grit your teeth as you saw what he was holding, a taser that was sure to paralyze you if it hit.

"Finally after running all the way here I finally caught you you little shit." He spat out.

You gave a blank look refusing to show any signs of fear or surrender.

"Who would've thought that if I turned you in I could get a huge reward talk about lucky." He continued to prattle.

With the amount of time he was taking up with his useless talk you could make your escape.
"I should thank that stupid old hag. If I didn't visit that ransacked cottage of hers I wouldn't have discovered your location. It's a good thing she died, after harboring a thing like you." He sneered giving a sickening laugh.

That last remark was the trigger, your trembling fists clenched hard until you felt your fingernails dig into your palms. Your eyes darken as your vision became red with rage at the mention of the one person you actually found fond of in this world.

"How dare you.." You said through your teeth.

But it's not like they're any better than I am.

"DROP DEAD!!" You released a loud screech showing off your paralyzing scream. The agent got caught in the sound wave his face contorted in both pain and something else. His body fell on the concrete unmoving.

"W-Wha-What did you-"

You cut the man off by stomping on his arm, a loud sickening cracks resonated followed by a loud scream. His arm bent in an unnatural angle as you could see his bone popping out. You stalked to him slowly, your actions even your face showing bloodlust.

Every time I think humans are redeemable I'm proven wrong.

You raised your clenched fist, your aura surrounding you turning black. A mass of black manifested around you as it stood hovering above the man, a humanoid image with black wings, or in other words a Kuro Yurei your own Black Ghost. Your eyes glanced on the man as he pitifully squirmed and begged.

"N-No please m-mercy.." He choked out.

You laughed a dry, humorless laugh.
"Mercy? Mercy?! After all that your race did to mine race from capturing to cruel experimenting you beg for mercy?! You humor me!"

The other men who were hunting you came and just saw the scene. They ran up to aid their fallen comrade, but you were one step ahead.

You brought down your fist commanding the Black Ghost to slaughter.

"Rot in hell." One final remark as your Black Ghost did it's job. The men all fell in a mess of blood and corpse. Their screams echoed in the empty street while you just blankly watched. You swiped a little blood off of your cheek after blood splattered everywhere. The deed was done and nothing was left but a crimson stained street and an eerie silence. Taking in deep breaths to calm yourself. The Black Matter phased away as you finally left the mess you made.

We're all just monsters.
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"Dazai we need to discuss something." Kunikida called to the detective, however the man could not hear him as he had his headphones in his ears again. He tried calling him again, but yet again he was ignored.

A vein popped on Kunikida's forehead out of annoyance. He whacked his notebook on Dazai's head.

"Owwww Kunikida you're so abusive." Dazai whined as he rubbed his sore spot.

"I've been calling your name a number of times but you just ignored me because of those stupid headphones idiot!" Kunikida yelled causing Dazai to pout. Atsushi observed the scene sweatdropping,
'Typical Dazai.' He thought.

"Anyway, there's something you should know about. It's a new case." Kunikida said catching both Dazai and Atsushi's attention.

"What is it Kunikida-san?" Atsushi asked.

"Apparently many authorities found a pile of corpses on the street near the harbor. Their faces were unrecognizable but they appeared to be government agents." Kunikida explained. Atsushi felt goosebumps at the description while Dazai just stared, but there was a slight serious look in his eye.

"The cause of the death is unknown but it seems as if a person is the culprit, and the Cheif wants us to investigate it." Kunikida added. Atsushi clenched his fist as he looked towards the ground.

"What kind of person is so cruel as to slaughter a bunch of people?" He mumbled.

"We're about to find that out. Atsushi, Kunikida let's go." Dazai said already heading out the door.

They all arrived at the scene, and the real life image was way worse than a description. Atsushi cringed as he looked upon the bodies, it looked like a mass murder.

"Ah, you're from the Armed Detective Agency aren't you?" A police officer came up to them saluting.

"That's right." Dazai then looked at the area, "Quite a mess here." He commented.

"Yeah, we suspect that this just happened last night because none of the corpses started decomposing yet. The blood is still fresh as well."

Dazai stalked up to the blood that painted the ground. He narrowed his eyes focusing on the subtle clues hidden from the naked eye. Kunikida's chatter with the police officer became distant in his ears. He looked upon the stone wall as he saw very faint scratches. There were tiny cracks in the concrete as if the force that killed these men weren't human. He glanced at the corner as he felt something. A presence of some sort?

'No human can cause this much damage unless...' He trailed off at the thought.

"Dazai-san do you think the Mafia did this?" Atsushi asked.

Dazai closed his eyes, "One would assume so, but I don't think the Mafia would just randomly slaughter a bunch of government agents unless they were working against them. Besides with the scratches on the wall and the cracks on the ground it's unlikely that a member of the Mafia's supernatural ability caused this."

All were in awe at his explanation.
"But if the Mafia didn't do this then who did?" Atsushi asked.

"That is the question at present Atsushi. And we're going to find out before anyone else gets word of this." Everyone was a little confused and really curious. What really caused this manslaughter?

"Then we should head back to the Agency and solve this further..Dazai?" Kunikida looked around as he didn't see any sign of the suicidal detective. Another vein popped on his forehead.

'THAT BASTARD!' Kunikida raged with a fiery aura gaining him weirded out stares.
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Dazai stuffed his hands in his pockets as he walked slowly into a factory, the same factory he confronted Atsushi about the White Tiger incident. Again he felt some sort of presence, that same feeling someone gets when they feel they're being watched. As if some sort of ghost is prowling about. He continued walking around as his eyes glanced analytically around in different directions. Out of the corner of his eye he spotted something slithering, a snake perhaps. Through his squinted vision he saw it was more whispy like...

'Some sort of matter?' He thought raising a brow.

Out of no where a tiny bang from the direction of the matter caught his attention. He straightened as he saw something flash behind the crates. He prepped himself, but then heard some sort of screech. He quickly plugged his ears with his earphones turning the music all the way up.

"So you revealed yourself huh?"

You jumped from behind going in for a hard punch, which Dazai only blocked. He held your fist as he observed your form. Shaggy (h/l) hair, dirty appearance, disorganized clothing with some holes near the heart area on your chest. They seemed to be holes that bullets pierce, he also saw bloody splotches near them. He felt curiosity building as he saw no signs of injury on you. You jumped back glaring menacingly, you once again summoned the black mass. Your Invisible Black Matter formed into a thin Black Ghost with black wings like an evil angel. Dazai's eyebrows raised in surprise as he never seen this kind of ability before. The notorious ability Rashomon harbored by his old Mafia acquaintance Akutagawa didn't compare to this.

'Would No Longer Human work?' He thought.

"Go away you human!" You exclaimed as you commanded the Black Ghost to attack Dazai. It formed something like deformed claws aiming to kill him. Dazai just barely dodged as he found it difficult to match up with it's pace.

'Interesting..'

He took one glance at your form as he saw you still glaring but held yourself like you were cold. Dazai thought for a minute simultaneously dodging the...thing attacking him before stopping.

"Ok! Hold your attack!" He exclaimed holding his arms up in surrender. You were momentarily confused as he didn't show hostility or even malice.

'Don't let him fool you (Y/n) he's probably doing this so you'll let your guard down.'

"I'm not going to attack if that's what you're wondering. I just want to chat." He said calmly. You blinked in surprise because he knew exactly what you were thinking. You let the Black Ghost fall back to you, but you were on high alert.

"How can I trust you human?" You spat out your question.

"I don't have any weapons on me." He said. You looked at his brown eyes in great suspicion, surprisingly he looked...honest.

'His eyes are kind of pretty.' You thought but mentally slapped your thoughts.
'Stop it he's a human, you can't have those thoughts.' Your thoughts jumbled together.

"Fine." You said sighing, "But that doesn't mean I trust you." You added glaring.

"Hey I wouldn't trust strangers either." He said. He walked up to you but you flinched and jumped back. He raised an eyebrow and decided to sit on the ground a few feet away from you. His action made you blink.

"I figured you would be more comfortable if I created some distance considering you jumped when I tried to get closer." He explained, you stayed quiet and eventually sat down yourself.

"Now let's get to know each other shall we? What's your name?" He asked. You remained silent facing away from the man.

"Ok I'll start with mine, my name is Dazai Osamu. And you are?" He gestured to you waiting for an answer.

"(L-L/n) (Y/n)." You stuttered, you hardly ever told anyone your name since you didn't want to be caught.

"Nice name (L/n)-san." He complimented, you stiffened slightly at the nice gesture this was the first time someone complimented you. Well except for one nice old lady who took you in.

"My next question, are you an ability user?" He asked. You looked at him confused.

"What's an ability user?"

Dazai raised a brow, "Basically it's a person who is able to use supernatural powers."

"No I'm not a so-called ability user." You said.

"Then how can you do that?" He asked pointing to your Black Ghost. It just sat near you like a roosting bird. You rubbed your arm not feeling the confidence to tell the man. It's your one biggest secret and you were determined to keep it hidden.

"I don't feel obliged to tell you that."

Dazai thought for a moment, he needed a way to convince you, and make you trust him. He wasn't going to get very far with this interrogation of he didn't.

"If you're feeling frightened to tell me there's no need. I'm not going to tell anyone. It's just you and me here." He said letting a comfortable feeling invade you. The calm expression he gave somehow made your adrenaline stop.

"Alright, but you must keep word to that." You said he just gave a thumbs up and gave a dorky expression.

"Ok..so this here," You pointed to the Black Ghost, "is a Black Ghost. It's an entity manifested from this element called Invisible Black Matter. I can control it because.." You paused taking in a deep breath, "I'm an Ajin."

You clenched your fists in your bent knees, "I'm an immortal being, seen as a monster by society."

Dazai stared at you, he put his fingers on his chin going into his train of thought again.
'Ajin..Ajin..the name rings a bell.'

"You don't seemed surprised or disgusted." You remarked.

"Oh I'm surprised alright, but not disgusted. You look like an ordinary human if anything." He said you blinked again before scoffing.

"Believe me I'd rather be an ordinary human blended into a bland society than a half immortal monster. I'm nothing but the governments plaything." You said bitterly as you stared at the ground. Dazai remained silent for a moment.

"(L/n)-san, I have one more question...did you kill those men?" He asked giving a serious look.

You gulped, "Y-Yes." You said shakily. You were shaking under his gaze but the you realized why you killed them in the first place. Your rage had started building up.

"They deserved it those cold-hearted, no good, greedy, human bastards!" You exclaimed as your fist made contact with the ground. You faced the floor as a shadow covered your eyes.

"I hate humans." You mumbled.

"So where will you go from here?" He asked standing up. He looked at you quizzically while stuffing his hands in his coat pockets. You somehow became somewhat shy under his gaze.

"I-I don't know.." You said quietly. Dazai saw the emotions on your face: uncertainty, and most of all fear.
"I made it this far running so I'll just run, and stay hidden." You finally said.

"For how long?" Dazai asked as if he wanted to argue with you.
"At this point forever."

"From your state you wouldn't look like you could last here."

"What do you know?! I'm immortal!" You argued, you peered at his face as you saw his serious expression yet something else...pity? No it wasn't pity, and unknown feeling came over you as you strangely felt comforted.

"I don't know anything about you, but I do know if you stay by yourself you will be hunted. By both the government but another very dangerous group will be after you if they hear about this. So I want you to come with me." He said. You gasped loudly looking at him with wide eyes. Your mind contemplated this.

'Should I go? I don't want to keep running all the time but what choice do I have? Why are you trusting him he's a a human, he'll betray you eventually. There's no one you could trust but yourself. But what if there's a slight chance..'

"I'll keep you hidden." He admitted. You squeezed your arms as you finally gave in.

"O-Ok.." You looked up and saw him giving you a smile. A very dazzling smile that made you feel warm. His eyes stared into yours, even with no words you know he's declaring that he'll protect you.

'Why do I feel warm?'

"Then let's go." He said. He walked up to you and gave out a hand. He waited for you, and you slowly grabbed his hand in yours. He hoisted you up and led you to the outside, to a new life.
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~Time Skip about 1 month~

Dazai kept his word throughout the entire time. He didn't say a word of your secret, that is until the Cheif of the Armed Detective Agency figured out there was something unique about you. You told your secret to the entire Agency, of course leaving out the part where you slaughtered those men. Dazai of course was there to defend you, and you were therefore put under his care. You eventually warmed up to everyone in the Agency, they were a special group of humans that was for sure, especially Dazai. Of course your mind still argued against developing a relationship with him. You had seen both of his serious side and his weird side, even learning of his special habit. It somehow just...happened, your trusted him enough. Now whenever you see him your emotions grow more intense not in an anger sense but something else. You could never figure out that something else.

"(Y/n) could you get Dazai again?" Kunikida asked you through the phone. You knew what he meant by that and sighed.

"You got it Kunikida-kun."

You went to where Kunikida said Dazai was. You found him in a tree, with a noose around his foot.
"Oh? Hi (Y/n)-san!" He exclaimed waving wildly.

You sweatdropped, "Back at it again with the suicide attempt huh Dazai-kun?"

"And it failed~"

You sighed once again. You went up to the rope to untie him. After undoing the very tight knot he fell faceplanted on the ground ungracefully.

"Ow.." Came Dazai's muffled voice. You helped him up, and he dusted himself off.

"Hehe I'm kind of embarrassed you saw me like that." He rubbed the back of his head and his cheeks tinted pink. You just gave a minuscule smile before scoffing softly.

"You're so weird, I never even knew there could be humans as weird as you."

He smiled as his hand found it's way to your cheek. He caressed it with his thumb and you felt your emotions spurring again.
"But you like the weird side to me."

"It's unique.." You responded. You stared into his eyes, you suddenly felt some sort of attraction as both of your faces kept leaning in. You almost felt his lips until a voice stopped you.

"Dazai-san!-" Atsushi stopped where he was as he saw how close both you and Dazai were. A flustered expression appeared on his face.

"O-Oh is this uh a bad time?"

You distanced yourself from Dazai as a heavy blush covered your face. Dazai sighed while rubbing the back of his head looking disappointed.
"Geez Atsushi you really have bad timing." He commented.

"A-Atsushi-kun did you need something?" You squeaked as more heat overcame your face.

"Oh yeah, Dazai needs to come to the Agency." Atsushi said. Dazai looked disheartened and was about to whine until you elbowed him.
"Don't shirk your work now go on!" You ordered.

"Fiiiiinnne." He drawled out and followed Atsushi.

Once they left you lifted your hand to feel the heat on your face.
'He was about to kiss me, he really was about kiss me.' A happy smile found a way in your face. The first time you smiled in God knows how long. It coursed through your body, and you felt giddy.

'But how long will that happiness last?' Somehow another voice in your head argued.
'You may be happy now but how long will it last? Remember you're immortal, what'll happens if he somehow manages to die. Even is unexpectantly or  of old age it doesn't matter but you'll be left alone. What if he's waiting to betray you, remember the slaughter you caused one month ago, you'll always be a monster.' The thoughts invaded you as the happiness slowly faded into something more of despair. You shook your head as you let memories with Dazai drown out the negativity. You walked back to the Agency feeling conflicted.
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You waited in the office for Dazai to come back from, wherever he went to. Atsushi came back before him, and he just said that Dazai went somewhere to investigate.

"I don't know he had this look in his eye when he said that." Atsushi explained.

You fell silent and let worry take over you. You knew Dazai was a very skilled detective, but what if he was in trouble still. You came to a decision as you stood up abruptly making the boy look up in concern.
"I'm going out."

"But you might get caught." He argued.

"But my worries are killing me, I'll be careful." You left the office and ran into the city streets.
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You found yourself in a dark alleyway after what seemed like hours of searching.
'Maybe he went back already?'

'Why are you so concerned anyway?'

Why were you so concerned? The answer was easy, you've developed an attachment to Dazai. Even though you thought you could never feel love for a human you were proven wrong. You ran down a corner, and a familiar tuft of brown hair caught your attention.

'I found him!'

"Dazai-san!" You called a smile appeared on your face as you ran to him.

"(Y/n).." He looked at you wide eyed. It wasn't out of happiness really it was more of worry.
"Why're you here?!" He asked roughly.

"You didn't come back, why're you so tense?" You asked.

"Who is this?" You heard another male voice which made you raise your guard. You looked beyond the shadows to see a man in a black trench coat with black hair, and soulless yet entrancing grey eyes. You saw another person, a women in a business suit with two guns. You narrowed your eyes seeing the man's  coat form into something. You gasped as his coat formed into some sort of beast.

"You're in the way, leave now." He ordered, his beast growled giving a warning. You refused to waver and stood your ground.

"I'm not leaving without Dazai." You stated.

"(Y/n) I know you mean well but you need to leave." Dazai said more like demanded.

"No way!" You exclaimed stubbornly.

The other man's eyebrows scrunched in anger.
"Insignificant..." He mumbled. He let the beast run wild. You pushed Dazai out of range taking the hit. You didn't realize the beast would be so fast and you didn't realize when the beast bit off your arm. Your endorphins weren't even fast enough as you felt an extreme pain. Your severed arm laid on the ground as you gasped and breathed. The beast went in for another strike, and Dazai flashed in front of you.

"Rashomon!"
"No Longer Human!"

Dazai activated his ability in a bright light he neutralized the beast. Dazai gave a blank look but you somehow could see him glaring.
"The result will always be the same Akutagawa."

The man named Akutagawa grit his teeth and glared back. You only saw rage in his expression.
"Dazai-san.."

He glanced back at you, and his eyes widened slightly. You Invisible Black Matter was doing it's job as it replaced the skin tissue. In just a few seconds another arm phased. Even Akutagawa looked shocked.
"W-What the?!" The women exclaimed.

"Remember I told you I'm immortal." You mumbled. You gave a hardened look at Akutagawa, "Now you'll face me!"

You let the Matter form into your Black Ghost. You controlled it to your will and let it attack. Akutagawa once again summoned Rashomon and the two entities battled it out.
"Are you an ability user?" Akutagawa asked.

"None of your God damn business!"

Your Black Ghost and Rashomon clashed again, and Akutagawa could feel himself become more pissed.
"(Y/n)!" You heard Dazai call. You ignored him once again letting your Black Ghost attack on whim.

"They're over here! The Mafia!" You heard other voices. Authorities came upon the scene and they looked in awe and confusion. They caught your attention and your eyes widened as you figured out they were government agents. You let the Black Ghost stop it's attack out of panic. Akutagawa stopped his hostile attack as well as he and the woman retreated.

"N-No.." You said shakily.

"(Y/n)!" Dazai called once again as he appeared next to you. He stood in front of you protectively as the agents came closer.

"I knew the Agency had another member, but I didn't think it would be an Ajin." An official said.

"You know what I am?"

"You're one of the creatures with the biggest bounty. The government would pay a high price to study a monster like you."

Dazai felt his fist clench and you grabbed the back of his coat. The agents gathered around you raising guns and other weapons.

"I would think that the government would pay the Armed Detective Agency plenty-"

"We don't need that useless money." Dazai said bitterly. The agent was taken a back but he composed himself.
"Even so, the Detective Agency cannot fight against the government. We can get out hands on her one way or another."

You thoughts went haywire again as the man kept talking.
'See no matter what, with what you are you can never attain that freedom..that happiness.'

'No I did attain happiness, even if for a short time I did. I won't be an inconvenience to them.'

You decided as a determined look cam on your face.

"If you want me!" You spoke out coming out from behind Dazai.
"You'll have to catch me first! Good luck cause I'll keep running!" You declared, the men looked ready to fire. You turned to the shocked detective giving him one genuine smile.

"Dazai-san.." You grabbed his face in both of your hands giving him a kiss on the lips. You moved against his showing him that this will be a final meeting.

Ever since I can remember I never belonged to society. I was never...normal.

Tears spilled from your eyes as they closed and you felt him kiss back.

But you showed me that all people are never normal.

You separated looking into his with your teary ones.

You took me in, and accepted me. Even though I was monster.

You whispered something in his ear, and let your Black Ghost wreak havoc giving your chance to escape.

For that I thank you, for showing me that I do belong. I'm sorry I never even got the chance to say what I never thought I'd say to a human..'I love you.'

You raced past a dazed Dazai leading the agents away from him. He turned and shouted your name in horror.

I don't know if we'll meet again, but I just wanted to show you how much I appreciate you. This is my final...

"Goodbye." You whispered as you vanished from his sight.

A/N: Whale then...uh, I don't know if this is what you were expecting. But somehow I came up with an angsty ending. I kinda got caught up in the moment. I added some sort of fluff I guess? Hey at least you got to kiss the guy. Did I get the Ajin part correct? I had to do a lot of research and even read a bit of the manga (which is interesting by the way, I'm going to read more.) Also just a request, I need new cover but I don't know how to make it like flashy or things like that. Do people just use photoshop, (which I don't think would work since I have a Mac.)
Next up:

Ranpo x Sweetooth!Reader

Akutagawa x Depressed!Reader