Great, so one-shot... And so if they're leaving that also means that other fights will end as well. Oh well, I guess people wouldn't want to see them[/sarcasm].
Though I like the beginning, thought it is the start of the longer flashback, but no, oh well. And it rather be Unohana at the end. Because when Shunsui was shown in despair in the middle of the chapter, the thought crossed my mind, comparing him to Unohana calmly drinking her tea somewhere.