Shi-Kai → Minatzuki
- release command → unknown
A giant manta ray type creature that emerges from the hilt of Unohana's zanpakutou. The inside of its stomach has healing abilities.
ban-Kai → Unknown
Unohana Retsu’s first appearance is in the emergency meeting of the Taicho gathered by Yamamoto Genryuusai Shigekuni. However she says nothing at this time, and the next time she is seen is at the time of Aizen Sousuke’s death, when she confirms with Komamura Sajin and Tousen Kaname that Aizen is dead.
After that, Yamada Hanatarou is “caught” by Ukitake Jyuushirou and brought before Unohana for judgment. Despite the reasons put forth by Ukitake, she determines that Hanatarou must be imprisoned on account of the fact that he is a seated officer in her division and the harm that the ryoka has supposedly done.
As head of the medical relief division, Unohana’s healing prowess is legendary and this is shown when she next makes a major appearance, that of the time when Abarai Renji challenges Kuchiki Byakuya and is defeated by the latter’s Ban Kai. She manages to save Abarai from certain death, delaying her arrival at the Soukyoku Stand for Kuchiki Rukia’s execution.
Kotetsu Isane, her Fuku-Taicho, expresses the regret that Yamamoto lied to Rukia regarding the release of the ryoka, and it is at this moment that Unohana arrives and tells Isane that despite the harshness of such a lie, if it allows Rukia to leave peacefully then it is for the better good.
After the chaos of Kurosaki Ichigo arriving at the scene, destroying the Soukyoku Stand and starting his battle with Kuchiki Byakuya, the respective Taicho then head off to their own battles. Unohana then releases Minazuki, even though it is not shown how, and saves all those hurt during the fighting, keeping Isane with her on top of Minazuki while allowing Minazuki to heal the rest inside of her (Minazuki). Arriving at the Relief Station, Unohana asks Minazuki to release everyone, seals Minazuki back, and asks the division members to keep the injured personnel for a time inside the station. She then asks Isane to follow her to Center 46.
They arrive at the scene in time to see Aizen defeating Hitsugaya Toushirou. After that, Unohana makes her presence known by saying, “Captain Aizen. No. You no longer have the right to be called Captain. The traitorous criminal, Aizen Sousuke.”
Aizen then replies “Domo,” (which is a pun, because domo can mean hello and thank you) and asks if Unohana guessed if he was there easily.
Citing the reason that the Offices of Center 46 was the only place he could hide at and the elaborate corpse doll, Aizen then points that she made two mistakes in her analysis. The first was that he was not here to hide, and the second was immediately shown as he does releases Kyoukasuigetsu in front of Unohana and displays the “corpse doll”.
He then proceeds to tell Unohana of his Zanpakutou ability, Complete Hypnosis, and of the fact that there was a third member of the clique, Tousen. He and Ichimaru Gin then teleport to Soukyoku Hill.
Unohana immediately requests Isane to find out his exact location. Upon successful location, Unohana then asks Isane to inform everyone of Aizen’s betrayal, including the ryoka, while she takes steps to save Hitsugaya and Hinamori Momo, the latter of which Aizen had fatally stabbed earlier, before Hitsugaya had made his appearance.
After ensuring that both would escape death at the moment, she leaves them in the care of Isane and travels via Minazuki to the Soukyoku Stand, where she tells Yasochika Iemura, the sanseki of her division, that the ryoka do not require help (upon her observation). She then settles down beside Kuchiki Byakuya and gently reproves him, saying that he has pushed himself too hard. She then calls Rukia closer upon Byakuya’s request, and thus is Byakuya’s reason for coldness revealed.
After that, Unohana stops two 11th Squad members from creating a ruckus at the 4th Division’s Relief Station, and also tries to get Hitsugaya to talk to Hinamori, who is unconscious. He, however, gives the reply that “the way I am now, I have nothing to say to her.”
The motherly character of Soul Society, Unohana has a gentle and warm personality that augments her appearance. Her healing powers cannot be denied and she also has a great sense of duty, in both the times that she orders Hanatarou’s imprisonment and Isane’s chasing of Abarai when he runs away with Rukia. With her grace and kind manners, she lets others know quietly that while she may be soft, she is not to be taken lightly. None has ever disputed this fact, for she is an indispensable part of Soul Society and the Gotei 13 Squads.
Isane’s zanpakutou becomes a three pronged sword upon release. Beyond that, little is known about Isane’s abilities. In the one and only instance that we have seen her release her zanpakutou, she was defeated in seconds by Kurosaki Ichigo, who didn’t even use his zanpakutou..
Shi-Kai:Itegumo (Frozen Cloud)
- release command: "Hashire!" ("Dash!")
Koutetsu Isane is the vice captain of the Fourth Division, also known as the Medical Unit, under Unohana Retsu. Isane is the older sister of one of the third seat shinigami of the Thirteenth Division, Koutetsu Kiyone. She is very tall at 187 cm (around six feet). She has platinum blonde hair and dark eyebrows. Her hair has two hair wraps on the left, and is set off by a second set of hair wraps just behind her right ear. Her face is has both very distinctive eyelashes and a very pouty mouth. She wears the standard shinigami robes, which happen to show off her tall, slim figure. She also wears the vice captain insignia for her division on her arm.
Isane is very devoted to her captain, and appears to be somewhat insecure about herself. She seems to be very empathetic to others feelings. For instance, when Yamamoto tells Rukia that he will grant her request to return Ichigo, Orihime, Ishida, and Chad to the real world safely, Isane feels that it’s cruel to lie to her outright like that. However, Unohana points out that since Rukia’s death in inevitable, it is just as well to let her die with no regrets. After the mess with Aizen’s betrayal, Isane can’t sleep and doesn’t want to wake Kiyone. However, Unohana is awake and invites her vice captain to sit with her until she can sleep. The only case that we have seen Isane fight is in the brief seconds that she, Marechiyo, and Choujirou were ordered to stop the escape of Renji and Rukia. However, in the brief interaction with Ichigo, she was defeated as easily as the other two. In the middle of the mess, Unohana used her zanpakutou to help heal Marechiyo and Choujirou and used her own power to heal Isane, who had not been hit as hard as her male comrades.
Unohana then proceeds to take Isane with her to investigate the mysterious circumstances of Aizen’s death. Upon discovering Aizen alive and his vice captain, Hinamori Momo, and the captain of the Tenth Division, Hitsugaya Toushirou, with fatal wounds, Unohana and Isane listen in wonder, fear, and disgust as Aizen reveals his plot to them. He leaves with Third Division Captain Ichimaru Gin, Unohana orders Isane to contact all the active captains, vice captains, and, to Isane’s surprise, all the ryoka who have had contact with the Fourth Division. This means that the only ryoka to not be contacted is Orihime, the only one who wasn’t injured.
Isane appears to be close to her sister Kiyone, though Kiyone is obviously the more intimidating of the two. She is also a member of the Shinigami Women’s Association. Isane is loyal to her captain, and is proud to serve her. She appears to believe in fairness for all. Her nurturing personality is well suited to the Fourth Division.