Ichigo is healing up nicely in Kirinden, to the point that when Kirinji strikes him and he doesn’t die, he’s deemed healed enough to head to the next palace. Renji, not one to be left behind, also takes Kirinji’s punch and gets to depart with Ichigo. Kirinji tells his brothers that they exceeded expectations, especially Ichigo. He can see why the Soul King has taken an interest in him.
Back down in Soul Society, the Central 46 have appointed Captain Kyouraku the new Head Captain and Captain of 1st Squad. His first official act is to strengthen the Gotei 13 by finally teaching zanjutsu to Zaraki Kenpachi. His teacher is to be the first Kenpachi: Captain Unohana Retsu, AKA Unohana Yachiru. The 46 forbade Zaraki from learning swordsmanship lest he grow strong enough to rebel, but desperate times…
Ichigo and Renji are rocketed from Kirinden to Gatonden, the Food Palace. There, Hikifune Kirio, AKA the Grain King, prepares them a massive feast of colossal food. There’s not trick to it, either: now that they’ve been healed in Kirinji’s baths, they must restore and augment their strength with large quantities of food.
After Ichigo briefly feels guilty, Kirio emerges from the kitchen to support Renji’s encouraging words: they are preparing for battle, just like those in Soul Society. Kirio’s far more slender figure is a result of her pouring her spiritual pressure into the food she’s making, which means Ichigo and Renji are becoming more powerful than they’ve ever been.
Kirio tells them that she invented Gikon, which eventually led to the creation of Kon and Soul Candies—an extremely useful development. The next member of Squad Zero invented the Zanpakuto, and were Ichigo and Renji not itching to hold swords in their hands once more, the next palace might be quite an unpleasant experience.
The comic relief provided by Ichigo, Renji, and the Squad Zero weirdoes is fun, but I appreciate that the balance of the episode adopts a far more serious tone. Unohana and Zaraki descend to Muken, the very lowest level of the Soul Society prison. A vast, virtually limitless empty space, it is the perfect place for to ridiculously powerful shinigami to have at it.
I always assumed that despite her role as Gotei 13’s chief medical officer, Captain Unohana concealed hidden, never-used powers and/or a dark past. Turns out it’s both: she was one of the OG Gotei 13 and former Captain of the 11th Squad. Before she joined the Gotei Unohana was the most notorious criminal in Soul Society
Zaraki is one of my favorite captains due to the fact he cares so little for the pomp and circumstance of his station, and simply wants to fight the strongest opponents possible. In Yachiru he certainly gets his wish. He may have defeated her to gain the 11th Captaincy (and gave her a scar on her chest that itches when he talks) but she makes it clear her hands were largely tied in that battle.
Here in Muken, there are no rules or boundaries. She can summon any and all criminal tactics and dirty tricks of yore in this rematch. As the first person Zaraki ever fought that he actually feared could kill him, he knows he might’ve gotten lucky that last time, and she even seems to use a bit of Aizen-like illusion to make him think she had killed him.
But she didn’t; she only brought him to the verge of death, which as she knows is the only way he gets stronger. It’s basically the opposite of everyone else (except for the Hulk). And since this “training” exercise is almost certain to be fatal to either Zaraki or Unohana, we see their lieutenants grappling with the fact they may never see their beloved captains again.
If Unohana is the one to emerge victorious, she’ll likely return to her 4th Division duties, but consider herself a failure. The job Shunsui gave her to do is to make one of their strongest warriors even stronger. If that means sacrificing herself so Soul Society can survive, so be it. If Zaraki returns from those black depths as the victor, he’ll be a changed—and even more utterly fearsome—shinigami.