The 6th saddest moment in the Bleach series is Rukia returning to the Soul Society and facing her punishment for her crimes committed in the world of the living. It’s a time to watch because of all the emotions that she is forced to suffer.
Rukia was sent to the world of the living to battle hollows, but she ran into Ichigo, gave him her powers, and got caught up in a major crime against the Soul Society. She eventually returns to face her punishment, but instead of getting something minor, she is sentenced to death. I mean, even her own brother refuses to help her out. It’s a crazy sentence for what should have been a minor crime.
Rukia is sent to sit in a cell by herself for days before the execution, looking out over the Sōkyoku, the very instrument that is going to be used to kill her. They leave her here and over time, Rukia makes peace with herself and understands why this is being done. She doesn’t blame anyone but feels remorse and a deep sadness because she is all alone. No Byakuya, no Ichigo, just her by herself and her thoughts. It’s an awful way to leave a prisoner to sit, knowing the next time they step outside into the sun, they will be killed.
We get to see all the happiness she had, knowing its all over. I mean, for an anime that is very deep and depressing time in the series. You are watching a character prepare for death, coming to terms with everything and just accepting her fate. Very dark and very sad, especially for an animated series.