Here we are at last: the long-awaited, extended reunion between Yuu and Mika, and I have to say…I was not disappointed. While other events took place on the margins, this is all about them, essentially a two-person play, with Yuu’s philosophy winning the day, at least for now.
Mika, absolutely feening for blood, takes the still-unconscious Yuu into a grocery store where little kids are hiding out. It’s all he can do to stop from popping one of their heads off and drinking the insides. But being called a “monster” by that kid is enough to stop him. He still has a measure of control, but it’s weakening.
After a brief chat with Asuramaru, Yuu wakes up, and Mika pounces on him as well. The difference is, Yuu doesn’t react the way the kid did. In fact, when Yuu figures out his blood will save Mika, he offers it willingly. It’s the least he can do for his family. Mika is appalled; he’s spent all this time resisting drinking human blood to avoid becoming a full, immortal vampire, and now Yuu is essentially telling him to toss aside the rest of his humanity to essentially scratch an itch that will never go away afterwards.
But you know what? Yuu doesn’t want to hear it. He’s not going to let Mika die, and even if Mika becomes a vampire, that won’t change the fact that he’s family and means everything to him. So Mika gives into Yuu’s kindness and practicality, and drinks deep. It’s an pointedly sensual scene. After drinking, Mika’s eyes turn red, but he remains essentially Mika. But he’s also still alive, which is all Yuu wanted. Mika thinks it’s not normal, but Yuu offers, who cares? What matters is they’re together again.
After being separated and being cared for by Guren, Yuu forced himself to survive (as the kids hiding in the store continue to do). He was driven by revenge but also lived in hope someone who needed him would one day come around. That someone was Mika, who wanted to save Yuu today but ends up being the one saved. He realizes Yuu has become much stronger than he was, and it gladdens him.
That doesn’t free Mika of his intense distrust and hatred of humans, but he can’t stop Yuu from returning to them, even at the edge of a sword. If Mika gets in the way of him and the rest of his family, he’ll push him aside. But he’ll also welcome assistance. Mika admits Shinoa and the others saved him, and agrees to help, but will only help save the four of them. That’s enough for Yuu; they can negotiate the details later.
As Shinoa & Co. arrive at an ominously empty airport with no vehicles to assist their retreat, Mika and Yuu drive to their location, and Mika takes the drive as an opportunity to tell Yuu what he’s been meaning to tell him all along, which he hopes will finally sway him to his line of thinking: they, the Hyakuka kids, were subjects of human experimentation furthered by the vampires and Demon Army. The humans who started the experiments ended up screwing up and killing off the world’s adults. Yuu knew he was a subject, but didn’t know about the apocalypse it caused.
See, says Mika, this is why you can’t trust humans. Instead, he wants to pull a U-turn and run away with Yuu to someplace far away; another paradise where they can be happy and free together. But again, Yuu shows how much he’s grown; even moreso than Mika. There is no paradise awaiting them out there. There never was. The last time they tried, their family was killed, and all they had to show for it was the present situation.
There’s no place else to run. And while some humans, like Kureto, experimenting on Shiho’s sister Mirai to produce the Seraph of the End, aren’t to be trusted or relied upon to not end the world (or what’s left of it), Yuu is still a human himself, and there are other humans he does trust and love who need his help. They, along with Mika, are why he’s survived this long, against all odds. So he won’t run away; he’ll run to them.