Fem Osamu Dazai

Dazai is a mysterious person, her true intentions are never revealed unless she reveals them. On most occasions, Dazai is overly dramatic. She takes most of her actions as a joke, and, although they are very well-thought plans, she does not credit herself for most of what she has done. Dazai likes to tease anyone and everyone, especially if it means that she can get a laugh out of it. As a suicide maniac, she often attempts to commit suicide in comical manners, but she oftentimes fails or gives up on it when such methods are painful. Dazai's regularly approaches woman and men to invite them to join her in a double suicide. While she is more lighthearted and comical, she still retains some of her darker personality. She is still able and proficient at coming up with long-run strategies, though she doesn't inform his teammates what they are until the time is right. When she is able to see through the enemies' schemes, no matter how complex, Dazai would sometimes plot to run along with a charade if she deems it necessary but Dazai is also willing to use dirty means to achieve her goals. Nonetheless, she does care for her teammates and watches out for them, especially Atsushi, a young woman, whom she sees with the greatest potential. Atsushi is like her daughter, sometimes protecting her from harm's way. Dazai despises dogs and will go out of her way to tease them with dog food and comical insults, she refers to Chuuya as a dog due to her underlying loyalty and submission.

Dazai is a young woman with mildly wavy, long, dark brown hair that reaches her butt and narrow dark brown eyes. Her bangs frame her face, while some are gathered at the center of her forehead. She is quite tall and slim in terms of physique, her breast cup size is 3C. For her attire, Dazai wears a long sand-colored trench coat, the belt of which she leaves untied. Under it is a black vest over a striped dress shirt that is light blue in hue. She wears a bolo tie, which is held by a brown ribbon and a turquoise pendant. She also dons beige pants, dark brown shoes, and has bandages wrapped around her entire body; only her face, hands, and feet are left uncovered.

No Longer Human allows Dazai to nullify others' abilities on contact. It relies on skin contact and is always active. As such, she can nullify any ability even while restrained as soon as it touches her.

Dazai talks informally in non-serious situations, she will sometimes dramatize her words in favor or getting a laugh out of it or receiving pity.