Sōsuke Aizen (Before Betrayal.)

Aizen is a polite, soft-spoken intellectual, often addressing his subordinates by their given names. He rarely shows any sign of alarm or distress, and often has entire situations planned out well in advance. Whenever confronted, Aizen is casual and uncaring, attempting to draw out a conversation and make small talk, which often infuriates those he is talking to. Aizen initially appeared to be a very kind, well-respected captain and was looked up to by many, especially his lieutenant, Momo Hinamori. However, this was just a mask to disguise his dangerously manipulative nature. In truth, he cares very little for his underlings and is willing to use almost everyone around him as pawns to achieve his goals. He is willing to stop at nothing to further his ambitions, including manipulating or killing anyone if he deems it necessary. He frequently toys with his underlings for amusement.

Aizen is a tall, lean man of light complexion, whose hair and eyes are a similar tone of brown (albeit the latter become more hazel later on in the colored manga). In his original guise as an affable Gotei 13 captain, Aizen kept his hair in a soft, shaggy curtain style and wore black, square-framed glasses, which along with his eyes (slightly droopy at the outer corners) lent him a disarming if not scholarly look. For attire, Aizen donned a standard Shinigami shihakushō with a long-sleeved captain's haori, its inside being a pale turquoise to signify the 5th Division.