It has been almost 30 chapters since we've seen Ukitake and Yamamoto and up until now they are nowhere to be found. Unohana or Kira MAY be treating Ukitake but they've been out of the picture for too long now. I know the focus of the story right now is Aizen versus the remaining able fighters but can't Kubo at least let us some glimpse as to where or what they are doing?
Another thing is Kensei and Wonderweiss' battle. I've been wanting to see how Kensei's bankai works but until now Kubo hasn't shown anyone anything about it yet. And come to think of it, if they are fighting at the same time and place as the other captains are, how come they don't join in the fight or at least finish each other first then join in the fight. I've had enough of this superficial fight between Gotei 13 and Aizen because Kubo makes it impossible for anyone to defeat seriously put damage to Aizen, much less defeat him. I want to see a normal fight where both sides take damage no matter how small or large it is.
Seriously, Kubo has too many underdeveloped characters in his roster right now. We've seen to much of the popular Gotei 13 captains. How can he not let the others shine like Ukitake or Shunsui? And of course the Vizard. Love and Rose are down with just a single strike considering they ought to be way more powerful than the current captains. They didn't even do their bankai which was disappointing. The remaining lieutenants too. What about them? Will they be just behind their captain's shadows following orders?
In another matter, Yammy should have gone by now. I mean, seriously, he's fighting two of the most proficient swordsmen in the Gotei 13, how can he not lose? And where in the world is Nel and Yachiru? Are they playing with each other?
Personally, I think Kubo has to get away from Karakura town at the moment. I think he has to finish Hueco Mundo first so that things will be somehow settled in and so that he can focus more on Karakura and start developing the other characters.