Atsushi Nakajima

"Motto: 'What's better than being alive?'"

Atsushi Nakajima (中島 敦,) is the main protagonist of Bungo Stray Dogs and a member of the Armed Detective Company

Appearance
Atsushi has light gray hair, pale skin, and is of average height with a slim build. He appears to have segmental heterochromia, consisting combination of purple with yellow along the bottom curve of his pupil. His hair is short and swept forward in loose spikes with a lock left long on the right side of his face. This uneven style is the result of bullying he suffered at the hands of other orphans in the orphanage, and he never fixed it.

Initially, he wears rags issued by the orphanage. After he joins the Armed Detective Company, Akiko Yosano and Doppo Kunikida issue him a white button up with the sleeves pushed to his elbows, a loose black tie, black pants, black, fingerless gloves, and a suspenders/belt combo with a long stretch of the belt dangling loose from the buckle.

Personality
Atsushi has severely low self-esteem due to his upbringing. He has a major complex about his worth as a person, as such he reacts negatively to people who judge others as unworthy. When people begin hunting him due to the seven billion yen bounty on his head, he becomes worried and continues to think that he is putting the Agency at risk, though is told by Doppo to learn how to become useful rather than worry about the Agency being attacked. As part of his low self confidence, when confronted with a dangerous situation, he initially tends to cower and/or has difficulty reacting to a situation or understanding what to do, being paralyzed in fear. However, while generally flighty and unsure of himself, his will hardens in tough situations, and he becomes steadfast and reliable. He is selfless and does everything possible to protect his friends, at one point using his body to cover up a bomb to protect the Agency members despite having never met them and on a number of occasions rises up and uses his power to save them.

He is easily scared and is somewhat naive and simplistic, believing things at face value. Despite this, he does have some common sense and is arguably one of the most "normal" members of the Agency. He tends to have exaggerated reactions towards the shenanigans of the Agency members and due to the strange circumstances and situations that follow them.

Although still struggling with his self-esteem, Atsushi gradually improves his confidence and sense of self after joining the ADA, along with his many confrontations with Ryunosuke Akutagawa. Strengthened by several missions and the clashes between the Port Mafia, Guild, and Rats in the House, Atsushi makes a goal for himself: prove his self-worth by helping and saving others, still plagued by the words of his former Headmaster.

He has a strong sense of morality, as seen through his interactions with Kyouka. He values life and tries to help his enemies, such as Kyouka and Lucy Maud Montgomery, both of whom were moved by his actions. He hates it when people die due to unfortunate circumstances or abuse their power to hurt others, as shown during his battle with Akutagawa.

Due to his poor upbringing, he has a mild obsession with money, though never to the point of greed. When he first meets Dazai and Doppo, he agrees to act as bait for the man eating tiger after learning how much the reward was. When he learned there was a reward for correctly guessing Dazai's original occupation, he comes up with a number of random guesses. He also becomes worried about how much Kyouka eats during their first outing due to the fact he had to pay for it (and she ate quite a bit). Despite this, he willingly helps others in need and money never comes before saving a life.

Ability
Beast Beneath the Moonlight (月下獣,): Atsushi has the ability to transform into a white tiger. At first, he doesn't seem to have much control over the transformation, likely due to the fact, or caused by, his unawareness of his state as an Ability user. After becoming an official member of the Agency and under the influence of All Men Are Equal, he gains more control over his transformations - as shown during his second fight with Akutagawa, when he breaks the transformation on his arms to escape.

Atsushi has shown several varying states of transformation, which range from a rather large full tiger form, to just slit pupils and tiger stripes on his face. He can transform and manifest various tiger body parts at will, such as tiger forearms with claws, or a tiger tail.

Also notable is that Atsushi's ability has extreme regenerative powers capable of healing bisection and amputation almost instantly.

He has shown to possess immense speed, durability, strength, stamina, and endurance on several occasions. He has also been shown to be a natural fighter in close combat and has shown to very cunning in battle in several fights.

However, after using his ability, Atsushi seems to become unconscious and collapses onto the ground.

Someone from the underground has put out a 7 billion yen bounty for him with the Mafia - it is later revealed that Fitzgerald is the one behind his bounty and the reason is because Atsushi is a guider to the book that every ability-user desires.

Background
Not much is known about Atsushi's background thus far. He grew up in an orphanage, where he suffered from severe abuse, both verbal and physical, from his caretakers, as well as social isolation from the other children. This history of mistreatment has evidently taken a huge toll on Atsushi's self-worth as an adult and has caused him to constantly question the value and usefulness of his life.

According to the headmaster, Atsushi's parents dumped in the trash. This headmaster becomes the foundation of Atsushi's warped self-worth. The abuse (presumably severe especially because of the tiger rampaging at night) led the headmaster to chain Atsushi in a cell with little to no food, and forcibly injecting him with either sedatives or nutrients. The headmaster emphasised Atsushi's hatred towards him, seemingly even encouraging it. Alongside the headmaster and other caretakers' verbal and physical abuse, Atsushi suffered at the hands of the other orphans. Oftentimes, the other orphans threw Atsushi under the bus when they could get in trouble, as the orphanage ran on some sort of point system that affected if and when they were fed.

Once he hits 18, Atsushi was kicked out of the orphanage because, though he was unaware of it at the time, he was transforming into a white tiger under the moonlight due to his ability and causing chaos.

Plot
Kicked out of the orphanage and aimlessly walking while suffering from starvation, he arrived two weeks later in Yokohama, where he met Dazai (who had been attempting to commit suicide by submerging himself in the river) and rescued him, though in the end, he was 'lectured' by the latter. Dazai who felt responsible after being 'saved' by Atsushi wished to help him, thus leading the former, himself and Kunikida Doppo to a teahouse.

As the three talked about the older men's job, Atsushi discovered that their task was to capture the Man-Eating Tiger (though no one was confirmed to be eaten). The conversation about the Man-Eating Tiger scared him to the point he almost left the place, if not for Kunikida hindering his escape even interrogated him as Atsushi stated that the Tiger was hunting him down.

Dazai then asked Atsushi to lend him a hand since Atsushi is the Tiger's prey, who rejected at first but due to his penniless circumstances, the poor kid had no choice but to cooperate with Dazai for the time being.

At a certain warehouse, Atsushi transformed into the Tiger the Detectives were looking for, attacking Dazai as he was the witness. Dazai successfully stopped Atsushi using his No Longer Human ability, transforming back Atsushi to his human state. Later, Kunikida and several members of the Agency arrived, asking what should they did to Atsushi since he knew nothing about what he had done.

Dazai calmly decided that Atsushi should join the Detectives. When Atsushi regained his consciousness, Dazai asked whether he remembered anything when he transformed, and the latter replied that he didn't remember anything, confused about what Dazai was asking. Until Dazai pointed at his right arm, that's when Atsushi finally acknowledged that he was an Ability-user.

Trivia

 * He and several other characters made appearances in mobile games, such as Love Heaven, Kimito Lead Puzzle 18, and Yumeiro Cast as limited time characters.
 * His favorite food is tea on rice (chazuke).
 * His choppy haircut is a result of another child cutting his hair as a prank when he was younger at the orphanage, and he had just let it grow as it is.