Osamu Dazai

"Motto: A bright and lively clean suicide."

Osamu Dazai (太宰 治,) is a member of the Armed Detective Company and was a former member of the city's worst underworld organization, the Port Mafia.

Appearance
Dazai has mildly wavy short dark brown hair and narrow dark brown eyes. His bangs frame his face, while some are gathered at the center of his forehead. He is quite tall and slim in physique.

For his attire, Dazai wears a long tan trench coat over a black vest and a striped dress shirt that is light blue in hue. He has a bolo tie around his collar, which is held by a brown ribbon and a turquoise pendant. He also dons beige pants, dark brown shoes, and has bandages wrapped around his neck and forearms, the reasons for the bandages are yet to be discovered.

In the mafia, Dazai wore a dark trench coat that reached under his knees. He also wore an eye patch which took up half of his face.

Personality
Dazai is a mysterious person, his true intentions are never revealed unless he himself reveals them.

Dazai is usually called lazy as Kunikida always scolds him for being unproductive and slacking off. Despite that, he has shown a sharp wit, deducing all the unlikely situations that led Atsushi to believe he was being stalked by a tiger when he actually was the tiger in question. He has complete confidence no matter what type of situation he is dealing with, be it combat or simply bad situations he himself created in the first place. In most occasions, Dazai is over dramatic, he takes most of his actions as a joke, and although they are very thought out plans he does not credit himself for most of what he has done.

Aside from his quick thinking, Dazai is the comic relief in the series and at times Dazai's soft side can be seen. However, Dazai mostly desires nothing more than to commit suicide.

Ability
His ability, No Longer Human (人間失格,), lets him nullify others' abilities on contact. His ability relies on skin contact, so he is unable to use it when he is restrained which is the only disadvantage to his ability.

Background
Dazai appears to be part of the Mafia prior to the story, and he is one of the Mafia Executives. He is said to have developed the stalking and torture techniques of the Mafia, and trained Akutagawa in using his ability. The reason on Dazai leaving the Mafia is currently unknown, but more then likely has something to do with his old friend Oda Sakunosuke, who he met in the Mafia.

Furthermore, it is unknown if he left on his own accord, or because he was expelled by Ougai Mori, as stated on Chapter 30.

Plot
Dazai first appeared floating down a river, apparently trying to commit suicide until he was accidentally found by a starved Atsushi. Afterwards, he and his colleague, Kunikida treated Atsushi to food while listening to his story about how he ended up at the river while hungry. He then introduced himself and Kunikida as part of the Armed Detective Company and they would like to hunt down the tiger that is apparently following Atsushi and terrorizing the areas wherever he went.

At night, while Dazai and Atsushi waited for the tiger to show up, he realized all of the clues that led Atsushi to be confused about the tiger was matching up to be the fact that Atsushi actually was the tiger. As Atsushi lost control of himself and transformed into a full-grown tiger, he was easily subdued by Dazai's ability, No Longer Human and lost consciousness. Dazai then brought Atsushi back to the dorm where the Agency members are staying. The next day, he called Atsushi for help because he was stuck in an oil barrel trying to commit suicide and gives him the address of the Agency at the same time.

Trivia

 * He, along with several other characters, made an appearance in the mobile game Love Heaven as a limited time character.
 * His constant attempts to commit suicide with a beautiful woman could be an allusion to his real life counterpart's attempted double suicide with Shimeko Tanabe and Hatsuyo Oyama. His attempt with his lover Tomie Yamazaki was ultimately successful.
 * It's also possible that his suicide attempts serve as a reference to No Longer Human 's protagonist Ōba Yōzō's multiple suicide attempts throughout the story, which is considered to be a reflection of Osamu Dazai's turbulent life.
 * He was the youngest boss in mafia history.
 * In real life, he is often grouped together along with Sakaguchi Ango and Oda Sakunosuke as the Buraiha or Decadent School. 
 * And on the series, this is often alluded, because the three used to meet in a certain bar, as seen in Dazai and the Dark Era, and illustrated on the calendar.
 * He is nicknamed as 'Bandage-wasting Device' by Kunikida at Chapter 2 / Episode 2.