Kyoichi Akikawa lost his family in a devastating plane crash when he was just a child.

"Will it really come someday?"
"Will the day ever come when I can truly move on from this pain?"

Kyoichi's stepsister Shizuku Akikawa has supported him all this time, while Yukitsuki Asaka bears a striking resemblance to Kyoichi's beloved older sister from before the tragedy.

As the paths of these three fated individuals converge, a mechanical god appears...

This is a story that heads towards the future.