Atsushi Nakajima

"Motto: 'The head may err, but never the blood.'"

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 purple and yellow eyes - purple towards the center of the iris, with a yellow ring around the outside. His hair is short and swept forward in loose spikes with a lock left long on the right side of his face. He is of average height with a slim build.

At the beginning of the series, he was wearing rags and one glove on his left hand. After he joins the Armed Detective Company, he wears a white button up with the sleeves pushed to his elbows, a loose black tie, black pants, 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. He has a strong sense of morality, as seen through his interactions with Kyouka. Generally flighty and unsure of himself, his will hardens in tough situations, and he becomes steadfast and reliable.

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.

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 was repeatedly told he was worthless and a nuisance.

Shortly before the series begins, Atsushi was kicked out of the orphanage because, although he was unaware of it at the time, he was transforming into a white tiger under the moonlight 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 was committing 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 an appearance in the mobile game Love Heaven as a limited time character.
 * His favorite food is tea on rice (chazuke) as shown in episode 1 of the anime where he eats stacks of bowls of it.
 * He is a character that panics easily, but puts others safety before his own as shown in episode 2 where he uses his body as a shield to cover a bomb, trying to save around a dozen of people.