Bungo Stray Dogs: BEAST


 * This article is about the Bungo Stray Dogs BEAST Light Novel. For the manga, see Bungo Stray Dogs BEAST (Manga).

Bungo Stray Dogs: BEAST (文豪ストレイドッグス　ＢＥＡＳＴ,) is a light novel by Kafka Asagiri based on the bonus story Beast: Akutagawa the White, Atsushi the Black, which was released alongside the official DEAD APPLE film premiere on 3 March 2018. A booklet summarizing the light novel's events was included in DEAD APPLE's DVD and Blu-ray release on 28 November 2018. The complete novel was released on 1 April 2019, including more content Asagiri incorporated and illustrations by Sango Harukawa.

Japanese
もし“ポートマフィアの禍狗”芥川龍之介が武装探偵社に入社していたら？

もし“月下獣”を宿す中島敦がポートマフィアに所属していたら？

妹を奪われ、怒りと破壊の衝動に身を任せる芥川と、『ポートマフィアの白い死神』として、敵対する者を屠り続ける敦.

ふたりの出会いが導く運命とは……!? それは“白”と“黒”が辿ったもうひとつの物語.

2018年公開の劇場版入場特典の小冊子に加筆修正した完全版が登場！

English
What if the Port Mafia's Hellhound, Ryunosuke Akutagawa, had joined the Armed Detective Agency? Likewise, what if Atsushi Nakajima belonged to the Port Mafia? In the parallel world of Bungo Stray Dogs: Beast, fledgling detective Akutagawa's desperate mission to rescue his younger sister from the Port Mafia's clutches brings him face-to-face with the organization's fearsome White Reaper…a.k.a. Atsushi Nakajima. What does fate have in store for the two beasts in this alternate tale of darkness versus light…?

Summary
When orphan Ryūnosuke Akutagawa kills a group of six outlaws who killed his friends, he encounters a bandaged man in black who originally planned on recruiting him. However, he sees how the boy is only bent on killing out of blind rage and revenge, a remark that angers Akutagawa. He tries to kill the man, but to no avail, much to his shock.
 * Chapter 0

The man then decides to choose another person to become his right-hand man. With Akutagawa at his limits, the man invites him to a rematch in the future. Until then, he declares that he shall hold on to Akutagawa's younger sister.

Four and a half years later, Akutagawa passes the Armed Detective Agency entrance exam after being taken in by member Sakunosuke Oda, which consisted of disposing a fake bomb held by detective Jun'ichirō Tanizaki. However, Akutagawa still has not passed the real test on whether he possesses self-discipline and morals befitting an Agency member, hence being secretly monitored by Tanizaki and Doppo Kunikida. Meanwhile, a squad of mercenaries face Atsushi Nakajima, feared as the Port Mafia's White Reaper, and the notorious Kyōka Izumi, leading them to complete their mission on orders of Mafia boss Osamu Dazai.
 * Chapter 1

Dazai later tells Atsushi of his plan's phase three; his next target, on whose documents are handed by Dazai's secretary Gin, is the Armed Detective Agency. Akutagawa tells the Agency members that his sister Gin was kidnapped by a "man in black", and he has since sought the help of Oda to train him become stronger. They then seek Ranpo Edogawa's help in finding Gin; though initially disinterested, he issues Akutagawa an OK card for him to fill with his fellow detectives when he satisfies and accomplishes their conditions of their choice, which Akutagawa performs as individually instructed.

On a chance encounter, Akutagawa meets Atsushi in Café Uzumaki, and the two find out that they both grew up as orphans. After they amicably exchange stories from their respective pasts, Akutagawa finds out from Atsushi's documents that he knows where Gin is, and the two get embroiled in a skirmish. Atsushi ends up retreating, while Akutagawa suffers from his wounds and is rendered unconscious. After Akutagawa is healed, he finds his OK card completely filled; in an Agency meeting, he recognizes Dazai's voice from a secret footage retrieved by Ranpo and Oda as the man in black's. He then storms the Mafia headquarters and kills off various armed guards.
 * Chapter 2

He later fights Kyōka and her phone-controlled Demon Snow, until Atsushi interferes. Tanizaki, having sneaked in using Light Snow, swipes Kyōka's phone which Akutagawa uses to manipulate Demon Snow and takes Kyōka hostage. While hiding, Tanizaki tells Akutagawa that Gin is due to be executed that day. Atsushi soon finds them, but Akutagawa blackmails him with Kyōka's life; out of fear, he is forced to lead Akutagawa to the boss. Meanwhile, Dazai begins phase four and leaves his office.

Along the way, Atsushi provokes Akutagawa that he shall never save his sister. Gin suddenly arrives to stop Akutagawa; as he embraces her, she stabs him and observes that he merely wishes to kill Atsushi rather than save her, both in the past and at present. Elsewhere, Dazai remotely deactivates Demon Snow's order after splicing bits of Akutagawa's voice. He then orders Atsushi to save Kyōka.

Oda heads to a bar to rendezvous with a Mafia accountant and acquire information that can threaten the Mafia in exchange for Akutagawa and Gin, but he instead meets a man in black who calls him "Odasaku". Meanwhile, Atsushi is haunted by a past order not to go to his former orphanage and engages Akutagawa in combat; the latter describes his emotion to be guilt.
 * Chapter 3

It turns out that Atsushi, against Dazai's orders, attacked the orphanage a year ago and confronted his orphanage director, who gave him a box. In a state of panic and fear, Atsushi killed him and found a watch in the box as his birthday present. The remorse-stricken Atsushi realized that he would never hear the one thing he wanted from the now dead director. He finally stitched up that the director had been hiding and covering up the tiger's accidents in the past, including the killing of a researcher.

In the midst of their battle, Gin urges Akutagawa to forget her and asserts that he is born to do evil. Atsushi transforms into a white tiger, and they both fall off the Mafia headquarters. Meanwhile, Dazai cheerily converses with Oda, until Oda turns hostile at the Mafia boss. Dazai ultimately reveals that their current world is one of many worlds and that they were friends in the original world; he soon imparts his goodbye to Oda.

As the clash draws to its conclusion, through a transceiver, Kunikida formally passes Akutagawa to the Agency. At a rooftop, Akutagawa spares Atsushi's life. Dazai arrives, fires Atsushi, and asks him to live in the outside world with Kyōka. Dazai then tells them of a certain Book that allows whatever written in it to become reality and is home to infinite worlds, including their current world. He ultimately reveals that he had planned for them to face and understand each other. As part of his fifth and final stage, Dazai steps off the ledge and commits suicide.

In the Agency, Akutagawa finally manages to learn non-combat skills with his ability and has been living as a full-fledged detective. Meanwhile, Atsushi awakes to Ōgai Mori and his assistant Elise. Mori, Dazai's Mafia predecessor who was believed dead, turns out to be the new orphanage director as part of Dazai's plan. After Atsushi is handed the watch given as his birthday present, Mori instructs him to break it. Atsushi refuses to destroy the item that he considers proof of his identity and past life, but he thinks back to Akutagawa's words—to "move forward"—and accepts his challenge to do so one day.
 * Chapter 4

Akutagawa meets with Oda on an assignment to rein in 180 bank robbers; the two have since grown to be the Agency's elite master-pupil detectives. Akutagawa recalls Dazai's words about their world being a mere shadow of the real world, though he believes that their lives are nonetheless genuine. He then pledges to find Gin and take his time until their world ceases to exist. Until then, Akutagawa vows to keep running to take his sister back, his life back, and become human.

Key Differences
The following are some differences of the alternate world in the novel to the original world:
 * Ryūnosuke Akutagawa's personality, while still intense and ill-tempered, has not been bred to be as homicidal or impatient. He's still largely himself but exercises a great deal of self-control not seen in the main universe. This Akutagawa succeeded in killing the men who killed the orphans he interacted with and was refused by Dazai to join the Port Mafia. In the Armed Detective Agency, his main goal is to find and retrieve his younger sister from the Mafia.
 * Atsushi Nakajima gains a reputation in the Mafia as one of its strongest members, known as the "White Reaper". He's forced to wear painful restraints to keep the tiger in check, and he uses the tiger's form frequently to defeat and often kill his enemies. At his core, he is still a fearful, timid person, wracked with guilt and remorse over the tiger going out of control and killing a researcher and his orphanage director before entering the Mafia. He is also fanatically devoted to Dazai for bringing him into the Mafia and letting him leave his past hellish life.
 * Kyōka Izumi betrayed the Port Mafia in the past and left. Unlike her main universe's counterpart, she returned to the Mafia and acts as Atsushi's personal partner.
 * Gin Akutagawa plays a much larger role than in the main universe. She still works in the Port Mafia, albeit as a secretary rather than as a commander of Black Lizard. She is more vocal than her main universe counterpart and holds a grudge against Akutagawa for 'abandoning' her in the past.
 * Sakunosuke Oda survives the war against Mimic, as he wasn't present during its main events and works in the Armed Detective Agency, acting somewhat as a mentor for Akutagawa. The orphans from the Dragon's Head Conflict also live with him, along with ten other children. Alive and well, he's in the process of publishing his first book. His friendship with Dazai is nonexistent, having never met Dazai, and Oda allows no friendship between them. This is the only universe in which he survives.
 * Osamu Dazai succeeds Ōgai Mori as the Port Mafia's boss. Dazai is much grimmer, although he still holds his dark, sardonic sense of humor at the worst of times. Dazai made many enemies, but the Port Mafia's influence spans even greater than Mori's influence during his leadership. Somehow, he managed to obtain the Book, and, thanks to No Longer Human, the Book's ability to merge and diverge realities does not affect him. This makes him largely similar to the main universe's Dazai, and they are essentially the same person living different universes. Protecting the Book is Dazai's main priority, aware it's the only universe Odasaku lives in and achieves his goal of becoming an author. As such, Dazai allows many hardships for himself for Odasaku's sake. In the end, however, the Book's knowledge and his own struggles overwhelm him, and after asking Atsushi to continue protecting the Book, he falls off the ledge of the main Mafia building.
 * Mori works at an orphanage and is a ex-Mafia member believed to have been killed by Mimic. He eventually tends to Atsushi together with Elise, a young adult nurse who acts as his assistant; she still refers to Mori as Rintarō.