James and his little sister Maiya currently live in their town's orphanage, fortunately, their town's policy towards sibling adoption requires the adopter to take in all of them. That way, the children are not forced to part.

On their way back to the orphanage from a bookstore, they end up stuck in an infinite loop and are unable to get out. A mysterious man appears before them, the cause, and offers a deal, he will find them a good person who wants to adopt them.

He left out the part about a new, dangerous world full of monsters and other evils, and the siblings turning into Metal Bat and his little sister Zenko.