Exogularity 02

The story of the rest of Strike Frontier that didn't happen from Exogularity 02

Operation Cherry Blossom happens as usual but with Kouzuki Yuuko as the 00 Unit. Through the dialogue with her, Target A finds out about the existence of parallel worlds. Yuuko realises that she might have just endangered the entire multiverse and has the Susanoo open fire but as soon as the cannon goes off, "something" happens.

The main character and pals wake up to find themselves back in 2016. At first they're relieved but then a woman appears before them- It's Yuuki Yuuko who had been sent to 2002 in their world. She tells them that at the same time as her appearance in this world, in 2002, giant coccoons now known as the Megalith also materialized in multiple spots around the world. The Daikuuji group believed her story and developed TSFs and put pressure on the government to make a squad for them in the SDF.

The return of the protagonists to this world in 2016 triggers the awakening of the coccoons and BETA emerging from them.

Thus begins Strike Frontier season 2, Backflow and Collapse.

Everyone except the protagonist and Minori (initially at least) loses their memories of the Alternative world.

Tashiro Hayato says that BETA invading the regular world was something they wanted to do from the very beginning- Their equivalent of the Aura Battlers showing up in Tokyo in Dunbine. He says that part 1's story being about saving everyone in Alternative was a way to set up the story for part 2's plot twist. Of course saving everyone was also something they wanted to do, but having a yin-yang balance is part of Age's identity at this point.

He says that it's unfortunate that they weren't able to make this happen and that he hopes that they'll be able to release it in some form someday, though it won't be in the same form as this. While it wasn't the case in part 1, part 2's story was to be linked very closely to the game's system. They do intend on doing something with the story and characters eventually.

The book also has the entire script to the first chapter of part 2's prologue, pictures of the 2016's world TSFs, and a bunch of sketches of the original Muv-Luv's characters in Extra clothes with no further explanation (also Haruka, Mitsuki and young Akane)