A tall, lean man with fair skin and brown hair and eyes, Aizen Sousuke presents a disarming, scholarly appearance with his soft shaggy hair and black square-framed glasses. His slightly droopy eyes lend him a gentle look, and he wears the standard Shinigami shihakushō with a long-sleeved captain's haori, its pale turquoise lining marking him as the 5th Division captain. His humble exterior and polite demeanor, using humble self-referring pronouns and respectful address for others, make him seem approachable and kind. He often shows genuine concern for others, whether questioning harsh judgments or offering comfort to his subordinates, his charisma drawing admiration from those around him.