In the aftermath of the attack on the 4th Division, Denji and Power are all healed up, and despite insisting otherwise, are by Aki’s side out of solidarity. They are, after all, three of the last surviving members. When the two leave shortly after Aki comes to, he asks the Curse Devil how long he has (two years), prepares to light a cigarette, and then can’t when he remembers Himeno.
Himeno gets her final wish: Aki lives to cry for her. As for Denji, he’s a little weirded out by how calm and cool he’s been about losing Himeno, the first person who wanted to be his friend. He wonders if he’d be just as indifferent if Power or Aki died. He even figures the loss of Miss Makima would only result in about three days of feeling bad, then he’d get back to living his life of meals and baths.
With Makima determined to strengthen what’s left of her now combined division, Denji and Power’s lives are about to get a lot less carefree. Deemed still too weak against the kind of devils they’ll have to hunt, Makima puts Himeno’s old sensei Kishibe (voiced by Tsuda Kenjirou) in charge of training them.
He immediately likes them, as neither are interested in revenge and will side with whoever will feed them (in Denji’s case) or whoever is winning (Power). They’re both the precise breed of fearless crazy needed to be effective devil hunters.
He pulls the two into a hug, and then casually breaks both their necks with his bare hands, leaving no doubt as to his toughness. After healing them with blood, he proceeds to kill or nearly kill the two again and again, deciding the best way to make them tougher is to hunt them until they’re capable of beating him.
While Denji and Power are enduring this, Kyoto’s Tendou and Kurose pay Aki a visit, and tell him it might be best if he quit while he’s still alive, like Madoka did. Unlike Denji and Power, Aki is still very much driven by the need for revenge against the devils that killed his family and Himeno. But to become strong enough to stay in the 4th Division, he’ll need to contract with stronger devils.
After Tendou and Kurose take their leave, a girl whose face we don’t see pays him a visit. While walking home from the graveyard, Denji and Power decide that the best way to defeat their new drunken teacher is to use their brains. Left unacknowledged is the fact that even if they put both their brains together they only end up with two balls of lint.
The next morning, they set up an ambush for Kishibe, all the while displaying a wholly unearned sense of confidence you can’t help but admire—they even wear glasses to look smarter. Kishibe easily defeats their surprise attacks, once again leaving them both on the floor, down for the count.
That said, he admired their attempt, and says he’ll give them the rest of the day off. The moment Denji drops his guard, he gets a thrown dagger to the forehead. Kishibe warns him and Power never to trust the words of someone hunting them. And so, the bloody trials continue.
Aki is escorted to the bowels of Public Safety headquarters by Tendou and Kurose, which serves as a prison for all of the devils captured alive. When Kurose asks if the girl at the hospital was Aki’s girlfriend, he says no; it was Himeno’s little sister, who brought letters Himeno wrote to her for Aki to read. Among them, Himeno discusses her unsuccessful attempt to get out of Public Safety with Aki.
As he contemplates his past, Tendou and Kurose take him to the cell of the Future Devil, one who took the eyes and sense of taste and smell from one human it contracted with and half the lifespan of another. Considering Aki has only two years left anyway (due to the Curse Devil), and his determination to destroy the Gun Devil, I’m certain the Future Devil can ask for whatever it wants, and Aki will sacrifice it.