“These angels have come down to perform for you … Are you ready?”

You might think this is just the Overture, but watch the PV again. Where do Maeda & Co come from? The stars, of course. It’s a play on the usual alien invasion trop, with a little twist. The aliens this time are really fucking pretty, and they come with a message.

“Just leave me, we decided that earlier, didn’t we?”

Is what Acchan says, imploring Mayuyu to leave her, presumably to die.

“But I can’t, there’s things you have to tell us, right? That’s why you’re here!”

“No. We came here for our own sakes, to change ourselves.”

Everyone who touches the girls contracts some sort of weird shit that gives them super TB and pretty much kills them.　This could be an allegory to the AKB48 policy of never touching anyone you don’t have close contact with. Aliens in this case probably referring to how AKB48 can’t have boyfriends and whatnot. Two girls are not affected by this Super TB, namely Mayuyu and Karen; We can see this when Karen stands alone in a sea of bodies, apparently the only survivor. There’s two ways to see Mayuyu’s immunity: It’s an in-joke about her cyborg self, or it’s an allusion to what Acchan said to her earlier about it already being decided. Mayuyu is not of this earth, in the way that the rest of the frontgirls are not of this earth. She came here earlier, as a scout.

The dance sequence is not so much a random thing, but rather Mayuyu being brought back to her alien self, by the hands that cover her eyes. She’s essentially a sleeper Cylon, with no memory of anything that happened before until she is brought back to the fold with those hands that cover her eyes. The dance sequence represents the awakening of Mayuyu’s self as an alien. The dance world and real world exist concurrently, but only a few have the ability to transition between both worlds with no harm being brought to them.

Then Mayuyu leads Acchan in a Psalm type sequence. She leads Acchan to the path of righteousness, for AKB’s name’s sake. Well except the water is not very still. And it’s Guam. Mayuyu doesn’t have any sort of weird reaction to the group of people waiting for both her and Acchan. That’s because she has been awakened and she is finally returning back to the fold. The dead AKB48 girls are now part of the dance world, due to their succumbing to the TB-like disease. But look at where everyone stands. Who’s behind Takamina, and between Sashihara and Oshima?

That’s right. Karen.

Karen is the true savior. She lives, but also gains the ability to move between the real world and the alien world. Mayuyu is a connection. In the real world, Mayuyu is the 3rd gen member that can still carry on after the pioneers have left. And she will be the bridge that facilitates the transition and transfer of power. The credit roll at the end is to encourage nostalgia (from the silly piano lines) and to ease the shock of just seeing the future of AKB48 in the span of six minutes.

Acchan uses 私たちが変わる為. But 代わる can also mean succession.