Unohana.

Unohana has the appearance of a slender and very youthful woman with blue eyes and black hair. She wears the standard Shinigami captain shihakushō apart from using an obi instead of the normal sash, which hides her well-endowed bosom. Her hair is long and is always worn as a large braid down the front of her body. Over 100 years ago, she did not have the large braid, instead styling in front of her as a loose ponytail. While maintaining a kind and gentle look at most times, during her battle with Kenpachi Zaraki, her eyes appear gloomy and menacing. She also wears her hair down for the first time, exposing a notable scar in-between her collarbone, inflicted by Zaraki when the latter was young.[6] Before he inflicted that scar on her, she did not tie her hair in front of her, instead wearing it down at all times.[7]