Retsu Unohana

is the Captain of the Fourth Division in the Gotei 13. She is one of the oldest and most experienced captains, and given her Division is of the healers, she is also a skilled healer.

Personality
Unohana is a soft-spoken, polite, and caring woman. She uses honorifics when addressing everyone, including her subordinates, and rarely shows panic or distress. Despite her gentle nature, several members of the Eleventh Division and even her fellow Captains fear her.

History
In Soul Society arc, she healed everyone in the execution site after Ichigo saved Rukia. Unohana also seems to let her division members go on leave to the real world from time to time; in the anime she gives Hanatarō Yamada permission to take a break in the real world shortly after the events in Soul Society.

Recently, Unohana and Isane have appeared alongside captains Kenpachi Zaraki, Mayuri Kurotsuchi, and Byakuya Kuchiki in Las Noches, her appearance effectively stopping the Exequias leader from doing further harm to Yasutora Sado. He calmly orders a retreat. She stops Isane from pursuing them, claiming that they are only there to heal the injured. She proceeds to heal Yasutora Sado and Gantenbainne Mosqueda.

It's hinted she has been a captain for over 200 years; along with captains Ukitake and Kyoraku. This makes her one of the eldest captains; although she doesn't appear very old. Also according to the former captains of the 5th and 7th squad she can be very frightening as the look on their faces implied they would never want to get on her bad side.

Zanpakutō
Minazuki (Purify the Flesh): In sealed form, Minazuki is slightly longer than an ordinary katana, and resembles a nodachi. Instead of tying it to her obi, Unohana carries her zanpakutō over her shoulder by a rope strap or lets Isane carry it for her.


 * Shikai:


 * Shikai Special Ability: When unsealed, Minazuki transforms into a giant, flying, one-eyed manta-ray. It's large enough to transport many people on its back (at least a dozen, based on its size when compared to those riding it). Additionally, it can swallow even more people and transport them in its stomach, healing their injuries at the same time. When Unohana reseals Minazuki, it dissolves into green mist and reforms into the sheath of her zanpakutō.