Rukia Kuchicki
Rukia, the second main character in BLEACH, is Byakuya's adopted little sister. About a year or so after his wife's death, he found Rukia in
the Shinigami school
and immediately adopted her. Adopting her was against the rules, but he promise his parents in front of their grave that this was going
to be the last time he would break a rule. Since
Rukia got adopted; she got the advantage of graduating early and entering the Gotei 13 without taking the exams. It is said that he adopted her because she
resembles Hisana but this is
not true. Hisana told Byakuya to not tell Rukia about her because she was ashame of herself for not being a good sister.
In the beginning, Byakuya doesn't really show much of a brotherly figure towards Rukia. Rukia even said that since she became part of the
Kuchiki family, he has never once
gave a slight care about her. This is true though because he shows no emotions for her. When it was announce that she was going to get executed,
he doesn't even try to go against the decision.
During the battle of Byakuya vs. Ichigo, Ichigo asked why he doesn't want to save Rukia.
Byakuya says that if Ichigo can defeat him, he will give him an answer. After Ichigo wins ( a very close match >=T too) Byakuya says
that he has to follow the rules and set out the standard for the rest of the Shinigami. Ichigo replies that if he was in Byakuya's situation, he would
break the rules. Byakuya seems to be surprise with this response. This seems to be the spark where Byakuya thinks deep about what's really important
to him. Later on when Rukia was going to get hit by Gin's soul cutter, Byakuya steps in and take the hit for Rukia. At this point, we see that he does care for Rukia.
Later he tells Rukia the truth about Hisana and he hold her hand =) how sweet.