Dazai is a young man with 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 terms of physique.
Dazai ware a black trench coat that reached under his knees. He also ware bandages over his right eye and his right arm is in a sling—presumably products of his suicidal pastimes. At some point, he was able to regain the use of his right arm.