Dazai and Chuuya, due to the alliance between the Armed Detective Agency and the Port Mafia, had a mission. To check out a mysterious mirror that suddenly showed up out of nowhere.

The mirror was easy enough to track down, but as soon as they see into it…they're surprised.

They see…a different version of themselves?

"Ah…" Dazai's fascinated, waving at himself as his redheaded counterpart waves back.

On the other hand, Chuuya checks his height and finds that he's taller than his blonde counterpart. He smirks as the blonde Chuuya pouts.

When Dazai curiously puts his hand on the mirror, he suddenly falls through. Of course, Chuuya follows after the idiot.

On the other side of the mirror was a library, along with their counterparts.

"Ha! I knew that mirror was a portal to another world!" Redhead Dazai yells in victory at the blonde Chuuya.

"Hai hai. You win…but now what?"

"This is…another world?" Dazai and Chuuya ask.

"Yeah. I'm Dazai Osamu."

"Nakahara Chuuya."

"I'm also Dazai Osamu."

"Same here. Nakahara Chuuya."

"…"

"How do I know you're the real deal?" Dazai asks.

The redhead Dazai sighs, "Tsushima Shuuji...is the name we both threw away."

"…I'll call you Osamu then," Dazai suggests, to which the redhead version of himself agrees.

As for the two Chuuyas… after a game of rock-paper-scissors, blonde Chuuya lost, so he took the name Nakahara.

"I have that same hat in my collection," Chuuya smirks.

"Really? Cool!" Nakahara smiles.

"Would you commit double suicide with me?" Dazai asks as he holds Osamu's hand.

"..." Both Chuuyas and Osamu were speechless.

"I thought you wanted to commit double suicide with a beautiful woman though?" Chuuya comments.

"I do! But this me and myself! We have a better chance of doing it!" Dazai says with stars in his eyes.

"Uh…maybe later?" Osamu sweat-drops, not knowing how to express his reluctance any other way.

"Aw~!" Dazai pouts.

After talking with…well, themselves at the Bar Lupin, they find out about Abilities and Taints.

"My Ability is No Longer Human."

Osamu chokes on his drink.

"Uh…that's actually the title of a book I wrote. One that I'm famous for," Osamu shakes his head.

"Heh~."

"Mine is For the Tainted Sorrow."

"I wrote that in my book of poems!"

"Really?"

"Un!"

Dazai smirks, "Even so…two Chuuyas…and they're still Chibi!"

"What did you say, Mackerel?!" Chuuya yells.

"What're you going to do about it, Hat rack!"

"Kill you, you bandage wasting machine!"

"Peach flower boy!" Nakahara joins in.

"Like I said, what does my face have to do with it?!" Osamu yells in reply.

As they drink, they get even rowdier…

"Sake!" Nakahara cheers as he lips his cup.

Chuuya suggests, "If you guys cultivate grapes...you can eat them as is, dry them to get raisins, juice them, and make some decent wine."

"Wine... I like that idea!" They toast to each other.

Meanwhile, a brown-haired man with a ponytail and a guy with short blue hair and yellow eyes came by.

"Ah! Odasaku, Dan!" Osamu greets before introducing Dazai.

"Odasaku?" Dazai questions as the silver-haired Odasaku nods, "Yeah," in an Osaka dialect.

Dazai sighs, "My Odasaku died...four years ago."

"...Died?" Odasaku, Dan, and Osamu blink in surprise.

"Un. He died in my arms even though his Ability was Flawless."

"..."

Dazai doesn't mind the silence, but asks, "Do you believe that a former assassin, a murderer can become a writer? Or...does he not have the right to write about life because he's killed before?"

"Why are you asking?"

"I'm asking for a friend..."

Osamu, ever the optimist, answers, "Well…I believe it can happen if he doesn't give up. As for the right to write about life…who the heck knows? If no one had the right to write about life, there'd be no books at all!"

Dazai smiles, "You're right…thanks."

"No problem!"

Then Dan just had to show him, "I wrote this."

Dazai Osamu: The Novel.

Then, a man with long dark hair and blue eyes came.

"Ah! Akutagawa-sensei!" Osamu greets with a smile more cheerful than before. Just like when his Akutagawa would give him that look, searching for affection of any sort.

"..." Dazai's speechless, flushed with embarrassment, face-palming before fainting.

Chuuya and Nakahara are laughing their asses off in the background.

When Dazai woke up, he's met with a Taint for some reason.

Narrowing his eyes, Dazai asks, "What do you want?"

"Your help in destroying all literature. In your world, your Abilities cause pain, yes?"

"Sometimes…" Dazai answers honestly, "But… You do realize this is all just an endless cycle, don't you?"

"Hm?"

"If you Taints are the negative emotions of humans, if you destroy literature, it's basically the same as destroying yourself, the very reason you even exist at all. Are you really OK with that?"

"Even so, I must."

Dazai ruffles own hair in frustration, "That's really stupid…! It's in human nature to share their stories, whether verbally or written down. They'll keep doing it even if they forget about literature entirely. The cycle would just continue...forever and ever. Do you really want to be stuck like that?!"

"...you may have a point."

"Of course, I do! Don't you know...humans are sinful and foolish beings. But, they're fine like that."

"Ha! I guess you're right. This war is...so pointless... But, what do we do now?"

Dazai smiles, "Keep a balance between the two, and it'll be alright."

Meanwhile, at Bar Lupin…

"Why do you work with Dazai again if you want to kill him?" Nakahara asks.

"Because...his predictions are almost always right," Chuuya answers.

"Ha…"

When Dazai wakes up again, he's back in the library.

"You OK? Did the Taint say anything to you?" Osamu asks, a bit worried.

"Yeah… We talked is all." Dazai then tells what he told the Taint.

All are speechless…but it makes sense.

Akutagawa decides to report it to the Alchemist. Just in case.

"Is there a Dan Kazuo in your world?" Osamu asks Dazai.

"...maybe. I haven't met him," Dazai shrugs.

"You should check. He may surprise you...and be the only guy that can tolerate you."

"Pfftt…you may be right," Dazai chuckles.

As Chuuya and Dazai prepare to leave, going back the way they came, a mysterious paper airplane hit Osamu in the forehead.

"Ow!" Osamu gets the plane before blinking, "Huh?" He opens it and reads it aloud: [So what?

Hah?

So what if you're not human? You shouldn't care about that. Life is short, so just do as you like, idiot.]

It was signed with a fox footprint.

"..." Both Dazais are speechless…but thankful.

"I guess I'll see you around then?" Osamu asks.

"Maybe…" Dazai answers, "And if I meet Dan Kazuo in my world, maybe he'll commit double suicide with me!"

"…maybe," Osamu and Dan sweat-drop.

Dazai drags a drunk Chuuya back through the mirror…before leaving him there again. The mirror itself disappeared though…whether it'll appear again or not is a mystery even Ranpo can't solve.

Omake:

Akutagawa-sensei got hit in the head with a manuscript.

The title was A Dialogue in Darkness.

Along with it was a note: [I know Akutagawa isn't your real name… it's a pen name. I don't care either. Just read it, you moron.]

Also signed by a fox footprint.

Akutagawa smiles, pocketing the manuscript in his robe before going to him room to read.

Omake 2:

"To the Stray Dogs," Dazai holds up his glass.

"To the Stray Dogs!" Everyone else cheers.

They toast.