It was the height of the Meiji Era in Japan when seventeen-year-old inventor Kashiwa Rei met his end at the hands of one of his own creations. Minutes earlier, he had witnessed the murder of his mentor and father figure, felled by a single shot. Two lives lost, four orphaned siblings, and a brilliant future that never came to be.

Or so it would have occurred if Rei had not been summoned by the three heirs of the Kingdom of Kounaria, in the wondrous world of Sylvaterra. The entire royal court pleads for the aid of their foretold Hero to confront an unprecedented threat: dozens of pirate vessels holding the populace hostage, ruthless and ravenous for power. It will fall to this inexperienced youth to halt their advance, free his people, and uncover a terrible secret that will forever change that fantastical realm. And to succeed, Rei must rely on the one thing he knows better than anyone: his brilliance to imagine and bring to life gadgets and inventions no one has seen before.